US008317826B2

(12) United States Patent (10) Patent No.: US 8,317,826 B2

Park et al. (45) Date of Patent: Nov. 27, 2012

(54) ABSORBABLE BULKY MULTI-FILAMENT (56) References Cited

DRAW TEXTURED YARN, MANUFACTURING
METHOD THEREOF AND MEDICALUSE U.S. PATENT DOCUMENTS
USING THEM 3,636,956 A * 1/1972 Schneider ..................... 606,224
6,743,505 B2 ck 6/2004 Antal et al.
(75) Inventors: Young Hwan Park, Anyang-si (KR): 2:32: R: 358, R al . . . . . . . . . . . . . . . . 424/422
Jung Nam Im, Gunpo-si (KR); Jae 7,445,793 B2 11/2008 Niwa et al.
Hoon Ko, Seoul (KR); Kyoung Woo
Lee, Incheon (KR); YongWoo Cho, FOREIGN PATENT DOCUMENTS
Seoul (KR) KR 638736 10, 2006
WO WO 2006/116000 11, 2006
OTHER PUBLICATIONS
(73) Assignee: Korea Institute of Industrial A. G. Mikos, et al.; Polymer; 35, 1068 (1994).
Technology, Chungcheongnam-do (KR) L. D. Harris, et al.; Journal of Biomedical Materials Research; 42.
396 (1998).
K.T. Paige, et al., Tissue Engineering; 1,97 (1995).
(*) Notice: Subject to any disclaimer, the term of this C. Schugens, et al.; Journal of Biomedical Materials Research; 30,
patent is extended or adjusted under 35 449 (1996).
U.S.C. 154(b) by 424 days. K.T. Paige, et al.; Tissue Engineering; 1,97 (1995).

(21) Appl. No.: 12/587,461 * cited by examiner

Primary Examiner — Julian Woo
(22) Filed: Oct. 7, 2009 (74) Attorney, Agent, or Firm — D. Peter Hochberg: Sean F.
(65) Prior Publication Data Mellin; Daniel J. Smola
US 201O/OO87856A1 Apr. 8, 2010 (57) ABSTRACT
(30) Foreign Application Priority Data
An absorbable multifilament draw-textured yarn having a
bulky structure, and a manufacturing method and medical use
thereof The absorbable multifilament draw-textured yarn is
Oct. 7, 2008 (KR) ........................ 10-2008-0098342 obtained by draw-texturing a multifilament made of an
absorbable polymer and has bulkiness and a superior soft
(51) Int. Cl. touch, which are the characteristics of draw-textured yarns.
A6 IB 7/04 (2006.01) As a result of partially imparting a bulkiness of 150-1000% to
A6DF 3/00 (2006.01) the multifilament draw-textured yarn, it is possible to culture
(52) U.S. Cl. ........................................ 606/230; 424/443 cells in the bulky structure, and the multifilament draw-tex
(58) Field of Classification Search .......... 606/228 231, tured yarn is suitable for cell delivery or drug delivery.
606/224; 424/422–424, 426, 443, 444
See application file for complete search history. 9 Claims, 5 Drawing Sheets
U.S. Patent Nov. 27, 2012 Sheet 1 of 5 US 8,317,826 B2
U.S. Patent Nov. 27, 2012 Sheet 2 of 5 US 8,317,826 B2
U.S. Patent Nov. 27, 2012 Sheet 3 of 5 US 8,317,826 B2

3.
U.S. Patent Nov. 27, 2012 Sheet 4 of 5 US 8,317,826 B2
U.S. Patent Nov. 27, 2012 Sheet 5 of 5 US 8,317,826 B2

Fig. 5
 US 8,317,826 B2
1. 2
ABSORBABLE BULKY MULT-FILAMENT Recently, in order to prepare a scaffold structure satisfying
DRAW TEXTURED YARN, MANUFACTURING Such requirements, researchers have made various attempts to
METHOD THEREOF AND MEDICAL USE prepare a polymer having a porous structure through various
USING THEMI techniques. Typical examples of Such techniques include: a
Solvent-casting and particulate-leaching technique (A. G.
CROSS-REFERENCE TO RELATED Mikos, etc. Polymer, 35, 1068, 1994), wherein single crystal
APPLICATIONS NaCl is mixed, dried and dissolved in water, a gas foaming
technique (L. D. Harris, etc., Journal of Biomedical Materials
This application claims foreign priority to Korean Patent Research, 42,396, 1998), wherein a polymer is inflated by
Application Serial No. 10-2008-98342, filed on Oct. 7, 2008, 10 using CO gas; a fiber extrusion and fabric foaming process
the content of which is incorporated by reference herein in its (K. T. Paige, etc. Tissue Engineering, 1,97, 1995), wherein a
entirety. polymer fiber is formed into a nonwoven fabric to make a
polymer mesh, a thermally induced phase separation tech
BACKGROUND OF THE INVENTION nique (C. Schugens, etc., Journal of Biomedical Materials
15 Research, 30, 449, 1996), wherein a solvent contained in a
1. Field of the Invention polymer Solution is immersed in a nonsolvent to produce
The present invention relates to an absorbable bulky mul porosity; and an electrospinning technique (Korean Patent
tifilament draw-textured yarn, and a manufacturing method Registration No. 638736) wherein a nanofiber yarn is elec
and medical use thereof, and more particularly to an absorb trospun to form foam cells in the strand of the nanofiberyarn
able multifilament draw-textured yarn wherein a bulky struc So as to increase the porosity of a three-dimensional cell
ture is partially imparted to a draw-textured yarn (hereinafter scaffold.
referred to as “DTY”), such that the absorbable multifilament In the case of the solvent-casting and particulate-leaching
draw-textured yarn easily performs cell culture, cell delivery technique, the preparation process is easy, but there is a prob
or drug delivery, and a manufacturing method and medical lem in that the pore on the surface layer is blocked, because
use thereof. 25 the Surface is rough and the salt remains on the Surface. In the
2. Description of the Prior Art case of the gas foaming method, pores which are weakly
One typical tissue engineering technique comprises: col interconnected are formed, and thus there is a limitation in
lecting a required tissue from a patient body; isolating a cell terms of the injection of cells. In addition, in the case of the
from the removed tissue; proliferating the isolated cell; seed fiber extrusion and fabric foaming process of forming a poly
ing the cell in an absorbable porous polymer Scaffold; cultur 30 mer fiber into a nonwoven fabric to make a polymer mesh, a
ing the cell in vitro for a predetermined period; and trans relatively high porosity can be achieved and the Surface area
planting the obtained hybrid-type cell/polymer structure into can be optimized, but low strength is still pointed out as a
the human body. After the transplantation is achieved, oxygen problem.
and nutrients are provided to the transplanted cells in absorb Meanwhile, in the thermally induced phase separation
able porous polymer due to the diffusion of body fluids until 35 technique, it is easy to control the size of pores, but it is
a blood vessel is newly formed. When the blood vessel is difficult to apply the separation technique in practice due to
formed to which blood is supplied, the cells proliferate and the formation of pores having a relatively small size. In addi
differentiate to form a new tissue and organ. During the for tion, in the electrospinning technique, it is not easy to achieve
mation of new tissue and organ, the polymer scaffolds are satisfactory porosity, thus making cell injection difficult.
degraded and then metabolized in the body. 40 Accordingly, with the conventional methods, it is not easy
Accordingly, in the field of tissue engineering, it is impor to control the pore size of the scaffold. Furthermore, the
tant to prepare an absorbable polymer scaffold that is similar Surface area and porosity of the resultant polymer Scaffolds
to the body tissue. are comparatively low and the open structures are not formed
In order to be used as a raw material for the polymer well. In addition, they are disadvantageous in that there are
scaffolds, the material should have sufficient mechanical 45 occurrences of closed pores on the Surface of the scaffolds,
strength, Such that it can properly serve as a scaffold so that the process is comparatively complicated, the gas or toxic
tissue cells can adhere to the surface of the material and form Substance maybe secreted during the preparation of scaffolds,
a tissue in a three-dimensional structure. It should also serve and salt remains in the scaffolds.
as a middle barrier, which is positioned between a trans Accordingly, the present inventors have made efforts to
planted cell and a host cell. For this purpose, it should be 50 Solve the problems occurring in the prior art and, as a result,
non-toxic and biocompatible such that neither blood coagul have prepared an multifilament yarn of less than 30 um in
lation nor inflammatory reaction occurs after the transplanta diameter using a conventional absorbable polymer for medi
tion. cal use, and have prepared a draw-textured yarn from the
In addition, such material should be absorbable so that the multifilament yarn so as to impart bulkiness and a soft touch.
transplanted cell properly functions as a new tissue in the 55 Furthermore, the present inventors have found that, when
body, it is completely absorbed by the body within a desired bulkiness is partially imparted to the draw-textured yarn, the
period of time. draw-textured yarn can easily perform cell culture, cell deliv
Typical examples of absorbable polymers which are cur ery or drug delivery during a Surgical operation so as to
rently generally used as raw materials for scaffolds include maximize the convenience of Surgery, thereby completing the
natural polymers, such as collagen, chitosan, gelatin, hyalu 60 present invention.
ronic acid or alginic acid, and synthetic polymers, such as
polylactic acid (PLA), polyglycolic acid (PGA) or poly-e- SUMMARY OF THE PRESENT INVENTION
caprolactone (PCL), or copolymers thereof.
Cell culture scaffolds prepared using such absorbable natu It is an object of the present invention to provide an absorb
ral polymers or synthetic polymers must have high porosity 65 able multifilament draw-textured yarn wherein a bulky struc
and high strength so as to facilitate cell injection and prolif ture is imparted to a draw-textured yarn (DTY) made of an
eration. absorbable polymer.
 US 8,317,826 B2
3 4
Another object of the present invention is to provide a BRIEF DESCRIPTION OF THE DRAWINGS
method for manufacturing the absorbable multifilament
draw-textured yarn. The above and other objects, features and advantages of the
Still another object of the present invention is to provide the present invention will be more clearly understood from the
medical use of an absorbable multifilament draw-textured following detailed description taken in conjunction with the
yarn which partially has a bulky structure. accompanying drawings, in which:
To achieve the above objects, the present invention pro FIG. 1 is a photograph of the inventive absorbable mul
vides an absorbable multifilament draw-textured yarn tifilament draw-textured yarn having a bulky structure of the
wherein a bulky structure is imparted to a draw-textured yarn present invention;
made of an absorbable polymer. 10 FIG. 2 is a scanning electron microscope image of the
As used herein, the term “bulky structure” refers to a struc inventive absorbable multifilament draw-textured yarn hav
ture in which pores greater than 1 Lum are present between ing a bulky structure of the present invention; and
fibers, and the term “bulkiness' refers to the diameterratio of FIGS. 3 and 4 are, respectively 100x and 500x magnifica
a portion having a bulky structure relative to a portion having tion image, respectively, which show the results of cell culture
no bulky structure. The bulky structure of the present inven
15 conduced using, as a scaffold, the inventive absorbable mul
tifilament draw-textured yarn having a bulky structure of the
tion has a bulkiness of 150-1000%, and preferably present invention.
200-600%. Also, the absorbable multifilament draw-textured FIG. 5 is a photograph of the absorbable multfilament
yarn of the present invention has pores of 1-150 um in the draw-textured yarn coupled with a Surgical needle.
bulky structure, such that it is suitable for cell delivery, cell
proliferation or drug delivery. DETAILED DESCRIPTION OF THE PRESENT
In the present invention, the absorbable polymer which is INVENTION
used as a raw material for the draw-textured yarn (DTY) is
selected from the group consisting of homopolymer and The present invention will be described in detail below.
copolymer of glycolide, glycolic acid, lactide, lactic acid, 25 The present invention provides an absorbable multifila
dioxanone, trimethylene carbonate and ethylene glycol. ment draw-textured yarn wherein a bulky structure is partially
Alternatively, an absorbable natural polymer selected from imparted to a draw-textured yarn (DTY) made of an absorb
the group consisting of collagen, cellulose oxide, chitosan, able polymer (see FIG. 1).
gelatin, fibrin, hyaluronic acid and alginate can be also used. The draw-textured yarn is obtained by draw-texturing the
The present invention also provides a method for manufac 30 multifilament made of an absorbable polymer and has bulki
turing an absorbable multifilament draw-textured yarn, the ness and a Superior soft touch, which are the characteristics of
method comprising the steps of: spinning an absorbable poly draw-textured yarns. According to the present invention, a
merto prepare a multifilament yarn; plying the multifilament bulky structure is partially imparted to the multifilament
yarns while draw-texturing the multifilament yarns to prepare draw-textured yarn, Such that the draw-textured yarn is Suit
a multifilament draw-textured yarn; drawing or stretching the 35 able for cell culture, cell delivery or drug delivery in medical
multifilament draw-textured yarn to impart a bulky structure applications.
to the draw-textured yarn; and twisting or braiding the mul As used herein, the term “bulky structure' refers to a struc
tifilament draw-textured yarn having the bulky structure ture in which pores greater than 1 um are present between
formed therein. filaments. The bulky structure is formed by drawing or
The manufacturing method of the present invention may 40 stretching the multifilament draw-texturing yarn made of the
additionally comprise a step of Subjecting a portion of the absorbable polymer. A bulkiness of 150-1000%, and prefer
twisted or braided multifilament draw-textured yarn to a coat ably 200-600% is partially imparted to the absorbable mul
ing process. tifilament draw-textured yarn through the twisting or braiding
The multifilament yarn comprises plurality of filaments process.
which have the diameter of 5-30 um, and the plied multifila 45 Specifically, the multifilament draw-textured yarn of the
ment yarn diameter of 40-1000 um. present invention has a bulky structure including pores of
In the manufacturing method of the present invention, the 1-150 um, and preferably 5-50 um, and thus it is easy to form
multifilament draw-textured yarn having the bulky structure open structures between the filaments due to high porosity.
is drawn or stretched so as to have a bulkiness of 150-1000%, The bulkiness of the multifilament draw-textured yarn may
and the absorbable multifilament draw-textured yarn partially 50 be freely controlled depending on its intended use Such as cell
having the bulky structure is used to provide a cell culture culture, cell delivery or drug delivery. If the bulkiness is less
scaffold. than 150%, the pores between the fibers will become smaller,
Furthermore, the present invention provides an absorbable so that cell proliferation in cell culture will become difficult,
multifilament Suture comprising an absorbable multifilament the amount of cell or drug that can be delivered into a living
draw-texture yarn which partially has a bulky structure in a 55 body will become smaller, and thus the utility as a scaffold for
draw-textured yarn made of an absorbable polymer. More medical applications will be reduced. On the other hand, if the
over, the Suture can be manufactured by coupling a Surgical bulkiness exceeds 1000%, yarn breakage rate will be
needle to the absorbable multifilament draw-textured yarn, increased due to the weak durability of the absorbable poly
followed by sterile packaging. mer, and pores between fibers will become excessively larger,
According to the present invention, an absorbable mul 60 leading to a decrease in the ability to retain a cell or drug.
tifilament draw-textured yarn suitable for medical use can be FIG. 2 is a scanning electron microscope image of the
provided by partially imparting a bulkiness of 150-1000% to absorbable bulky multifilament draw-textured yarn of the
a draw-textured yarn made of an absorbable polymer. present invention. As shown therein, the absorbable multifila
The inventive absorbable multifilament draw-textured ment draw-textured yarn has pores in the bulky structure. The
yarn which partially has a bulky structure is useful for cellor 65 degree of bulkiness or the size of pores is controllable
drug delivery, and thus is useful as a cell culture scaffold or a depending upon drawing or stretching conditions during the
medical Suture. manufacture of the draw-textured yarn.
 US 8,317,826 B2
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It is to be understood that the pore size can be suitably On the other hand, if the diameter of single filament in the
controlled depending on the size of cell or drug selected. inventive absorbable multifilament yarn is greater than 30
Specifically, the bulky structure of the multifilament draw um, the degradation rate of the yarn after cell culture, cell
stretched yarn includes pores having a size of 1-150 Lim, and delivery or drug delivery can be slower, and the yarn will be
preferably 5-50 um. If the pore size is less than 1 um, the pores stiff so the convenience of surgery will be reduced.
between the fibers of the yarn will become smaller, so that cell If the elongation of the multifilament yarn made of the
proliferation in cell culture will become difficult, the amount absorbable polymer is less than 20%, the texturing workabil
of cell or drug that can be delivered into a living body will ity of the yarn will be rapidly deteriorated. The higher the
become smaller, and thus the utility as a scaffold for medical elongation of the yarn, the better the workability; however, if
applications will be reduced. On the other hand, if the pore 10
the elongation of the multifilament yarn is more than 80%, the
size exceeds 150 lum, the breakage rate of the yarn will be workability of the yarn will be significantly deteriorated.
increased due to the weak durability of the absorbable poly Accordingly, the multifilament yarn which is used in the
mer, and the pores between the filaments of the yarn will present invention preferably has an elongation of 25-40%.
become excessively larger, leading to a decrease in the ability
to retain a cell or drug. 15 Also, if the tenacity of the multifilament yarn is less than 2.0
Because it is preferable that a bulky multifilament draw g/d, the texturing workability of the yarn will be deteriorated,
textured yarn for the purpose of cell culture or drug delivery and if it is more than 9.0 g/d, the soft touch of the draw
is degraded and absorbed in vivo after achieving the purpose, textured yarn will be reduced.
it should be made of an absorbable polymer. The diameter of the plied multifilament yarn obtained in
The absorbable polymer which is used in the present inven step (2) may vary depending on the application field and
tion is not specifically limited as long as it is a biocompatible intended use of the resultant yarn. If the resultant yarn is
resin known in the art. Examples of the absorbable polymer applied to medical sutures, the plied multifilament yarn will
include natural polymers and synthetic polymers. The preferably have a diameter of 40-1000 um, and more prefer
absorbable synthetic polymer which is used in the present ably 40-800 um.
invention is selected from the group consisting of homopoly 25 If the diameter of the plied yarn is less than 40 um, yarn
merand copolymer of glycolide, glycolic acid, lactide, lactic breakage will be likely to occur during the stretching/draw
acid, caprolactone, dioxanone, trimethylene carbonate and twisting process and the efficiency of production of the bulky
ethylene glycol. structure will below, and the tenacity of the yarn will below,
Also, examples of the absorbable natural polymer which leading to a decrease in the convenience of implantation. If
can be used in the present invention include collagen, cellu 30
the diameter is more than 1000 um, it will be difficult to apply
lose oxide, chitosan, gelatin, hyaluronic acid and alginate. the yarn in vivo by a surgical operation using a conventional
The present invention provides a method for manufactur Suturing technique, and the foreign body reaction of the poly
ing an absorbable multifilament draw-textured yarn wherein mer used in vivo will be increased.
a bulky structure is partially imparted to a draw-textured yarn Subsequently, the plied multifilament yarn made of the
(DTY) made of an absorbable polymer. 35
absorbable polymer is subjected to a draw-texturing process
More specifically, the manufacturing method of the present
invention comprises the steps of to prepare a multifilament draw-textured yarn. In order to
(1) Spinning an absorbable polymer to prepare a multifila ensure the texturing workability and the quality of the draw
ment yarn; textured yarn, the draw-texturing process is carried out at a
(2) plying the multifilament yarns with each other while 40 linear velocity of 200-700 m/min, and preferably 250-400
draw-texturing the yarns to prepare a multifilament m/min, at a drawing ratio of 1.01-1.8, and preferably 1.02
draw-textured yarn; 1.7.
(3) drawing or stretching the multifilament draw-textured Step (3) of the manufacturing method of the present inven
yarn to imparta bulky structure to the textured yarn; and tion is a step of stretching or drawing the multifilament draw
(4) twisting or braiding the multifilament draw-textured 45 textured yarn prepared in step (2) to impart a bulky structure
yarn having the bulky structure therein to impart to the draw-textured yarn. In step (3), one process of impart
mechanical strength and dimensional stability. ing the bulky structure is carried out by winding the absorb
Moreover, the manufacturing method of the present inven able multifilament draw-textured yarn on a stretchable rack,
tion may additionally comprise a step (5) of performing coat and then stretching the wound yarn by 3-10%, and preferably
ing on a portion of the multifilament draw-textured yarn 50 4-7%. If the stretch ratio is less than 3%, it will be difficult to
imparted with dimensional stability by the twisting or braid make the bulky structure, and if it will exceed 10%, yarn
ing process. breakage will be likely to occur.
In step (1) of the method, a synthetic absorbable polymer Another process of imparting the bulky structure is carried
selected from the group consisting of homopolymer and out by a drawing method in a continuous process.
copolymer of glycolide, glycolic acid, lactide, lactic acid, 55 Step (4) of the manufacturing method of the present inven
caprolactone, dioxanone, trimethylene carbonate and ethyl tion is a step of twisting or braiding the multifilament draw
ene glycol, or an absorbable natural polymer selected from textured yarn having the bulky structure formed in step (3).
the group consisting of collagen, cellulose oxide, chitosan, The twisting or braiding process is carried out in order to
gelatin, fibrin, hyaluronic acid and alginate is through a spin improve the cohesion, mechanical properties and use conve
nerette to prepare an multifilament yarn having the diameter 60 nience of the multifilament draw-textured yarn. After the
of 5-30 um for single filament. process of imparting the bulky structure, the multifilament
The absorbable multifilament yarn of step (1) is an mul draw-stretched yarn is separated from the rack, and then
tifilament yarn having the diameter not greater than 30 um, twisted at 200 turns/meter or less in order to maintain the
while it has satisfactory properties of a tenacity of 2.0-9.0 g/d bulky structure while enhancing the cohesion of the yarn.
and an elongation of 20-80%. Thus, it can minimize the 65 Meanwhile, if the absorbable multifilament draw-textured
occurrence of yarn breakage in the Subsequent draw-textur yarn having the bulky structure is used as a Suture, a braiding
ing process. process may be used instead of the twisting process. The
 US 8,317,826 B2
7 8
braiding process is carried out in Such a manner that the medical suture, it will be useful for cell culture, cell delivery
predetermined portion is not braided to retain partially bulky or drug delivery, and thus can perform cell or drug delivery
Structure. through a Surgical operation, thereby maximizing the conve
The absorbable multifilament draw-textured yarn of the nience of Surgery.
present invention manufactured through the above-described In addition, the suture of the present invention can be
steps has a bulky structure including pores of 1-150 um in manufactured by coupling a Surgical needle to the absorbable
diameter, and preferably 5-50 um in diameter. The size of multifilament draw-textured yarn, followed by sterile pack
pores in the bulky structure is easily controlled, and the bulky aging. FIG. 5 displays the Surgical needle coupled to the
structure shows high porosity. absorbable multifilament draw-textured yarn.
The manufacturing method of the present invention may 10 Hereinafter, the present invention will be described in fur
additionally comprise, after step (4), a step (5) of subjecting a ther detail with reference to examples. It is to be understood,
portion of the twisted or braided multifilament draw-textured however, that these examples are for illustrative purposes
yarn to a coating process to further enhance the dimensional only and are not to be construed to limit the scope of the
stability of the yarn and to reduce tissue drag during the present invention.
implantation. 15
By additionally imparting cohesion to only a portion of the EXAMPLE 1.
bulky multifilament draw-textured yarn trough the twisting or
braiding process and the coating process, a bulkiness of 150 Manufacturing the Multifilament Draw-Textured
1000%, and preferably 200-600% is partially imparted to the Yarn Having Bulky Structure 1
incoherent portion of the multifilament draw-textured yarn.
Specifically, in the coating process, a coating solution con Poly(glycolide-co-lactide) consisting of glycolide and lac
taining 1-10 wt % of an absorbable polymer resin in an tide at a weight ratio of 90:10 was melt-spinning by a con
organic solvent is applied to the twisted or braided multifila ventional method to prepare a multifilament yarn consisting
ment draw-textured yarn by a conventional method such as of 56 filaments each having a diameter of 15-17 lum. The
dip coating or spray coating. 25 multifilament yarn showed a tenacity of 7 g/d and an elonga
Herein, the absorbable polymer resin which is used in the tion of 40%.
coating solution to form a thin film layer on the yarn Surface Four bundle of multifilament yarn consisting of 56 fila
is selected from the group consisting of homopolymer and ments was plied using Murata 33H (belt type; belt angle
copolymer of glycolide, glycolic acid, lactide, caprolactone, 110), while they were twisted on the first roller in the Z-di
dioxanone, trimethylene carbonate and ethylene glycol, oran 30 rection, untwisted on the second roller, and then heat-set at
absorbable natural polymer consisting of the group consisting 170° C., thus preparing a draw-textured yarn (DTY) consist
of collagen, cellulose oxide, chitosan, gelatin, fibrin, hyalu ing of 224 filaments. The draw-texturing process was per
ronic acid and alginate. Preferably, either a copolymer of formed at a draw ratio of 1.024 and a linear velocity of 250
glycolide and lactide (30:70) or polycaprolactone is dissolved m/min.
in ethylene acetate or methylene chloride and used as the 35 Then, the draw-textured yarn made of poly(glycolide-co
coating resin. lactide) was wound on a stretchable rack, and then stretched
Also, for the convenience of implantation, a softener Such by 4%, thus preparing a multifilament draw-textured yarn
as calcium Stearate may be added to the coating solution. having a bulky structure.
The present invention also provides a cell culture scaffold The prepared bulky multifilament draw-textured yarn was
which allows a cell or body tissue to proliferate in the bulky 40 separated from the rack, and then twisted at 80 turns/meter.
structure of a multifilament draw-structured yarn wherein the The twisted multifilament draw-textured yarn was cut to a
bulky structure is partially imparted to a draw-textured yarn length of 45 cm, and the remainder other than about 5 cm of
(DTY) made of an absorbable polymer. the central portion of the cut yarn was coated under tension
The bulky structure of the absorbable multifilament draw such that the yarn was stretched by about 4%. Then, the
textured yarn which partially has the bulky structure includes 45 coated yarn was dried for about 3 seconds in a convection
pores of 1-150 um, and preferably 5-50 um, and thus shows oven at 40°C. The coating process was carried out using a
high porosity. Accordingly, the closing of pores the scaffold coating solution containing 2 wt % of a copolymer of gly
can be avoided. collide and lactide (30/70 w/w) in ethylene acetate.
FIGS. 3 and 4 are, respectively, 100x or 500x magnifica
tion photographs showing the results obtained by culturing a 50 EXAMPLE 2
cell (NIH 3T3 cell) for 3 days using the inventive absorbable
multifilament draw-textured yarn as a scaffold. Manufacturing the Multifilament Draw-Texturedyarn
The results shown in FIGS. 3 and 4 reveal that the absorb Having Bulky Structure 2
able multifilament draw-textured yarn which partially has the
bulky structure in the draw-textured yarn made of the absorb 55 Polylactide was melt-spinning by a conventional method to
able polymer can achieve cell culture in the bulky structure. prepare a multifilament yarn consisting of 72 filaments each
Furthermore, the present invention provides an absorbable having a diameter of 10-12 um.
multifilament Suture comprising an absorbable multifilament The multifilament yarn showed a tenacity of 3.2 g/d and
draw-textured yarn wherein a bulky structure is partially elongation of 30%.
imparted to a draw-textured yarn made of an absorbable 60 Four bundle of multifilament yarn consisting of 76 fila
polymer. ments was plied using Murata 33H (belt type; belt angle
The absorbable multifilament suture of the present inven 100), while they were twisted on the first roller in the Z-di
tion comprises an absorbable multifilament draw-textured rection, untwisted on the second roller, and then heat-set at
yarn which partially has a bulky structure including pores of 115°C., thus preparing a draw-textured yarn (DTY) consist
1-150 lum, and preferably 5-50 um, and which partially has a 65 ing of 288 filaments. The draw-texturing process was per
bulkiness of 150-1000%. Accordingly, when the absorbable formed at a draw ratio of 1.63 and a linear velocity of 300
multifilament Suture of the present invention is used as a m/min.
 US 8,317,826 B2
9 10
Then, the draw-textured yarn made of polylactide was for cell delivery or drug delivery, and thus is useful as a cell
wound on a stretchable rack, and then stretched by 5%, thus culture scaffold or a medical suture.
preparing a multifilament draw-textured yarn having a bulky In addition, the inventive absorbable multifilament draw
Structure. textured yarn having the bulky structure can perform cell or
The prepared bulky multifilament draw-textured yarn was drug delivery during a Surgical operation, and thus maximize
separated from the rack, and then twisted at 150 turns/meter. the convenience of Surgery.
Although the preferred embodiments of the present inven
The twisted multifilament draw-textured yarn was cut to a tion have been described for illustrative purposes, those
length of 45 cm, and the remainder other than about 4 cm of skilled in the art will appreciate that various modifications,
the central portion of the cut yarn was coated under tension 10 additions and Substitutions are possible, without departing
such that the yarn was stretched by about 5%. Then, the from the scope and spirit of the invention as disclosed in the
coated yarn was dried for about 3 seconds in a convection accompanying claims.
oven set at 40°C. The coating process was carried out using What is claimed is:
a coating solution containing 2 wt % of a copolymer of 1. An absorbable multifilament draw-textured yarn com
glycolide and lactide (30/70 w/w) in ethylene acetate. 15
prising an absorbable polymer, wherein the absorbable mul
tifilament draw-textured yarn partially has a bulkiness of
EXAMPLE 3 wherein said bulkiness is a diameter ratio of a portion of the
absorbable multifilament draw-textured yarn having a bulky
Manufacturing the Multifilament Draw-Textured structure relative to a portion of the absorbable multifilament
Yarn Having Bulky Structure 3 yarn having no bulky structure, said bulky structure being a
structure of the absorbable multifilament draw-textured yarn
Poly(glycolide-co-lactide) consisting of glycolide and lac having pores between said filaments, said pores being greater
tide at a weight ratio of 90:10 was melt-spinning by a con than 1 um in diameter.
ventional method to prepare a multifilament yarn consisting 2. The absorbable multifilament draw-textured yarn
of 56 filaments each having a diameter of 15-17 lum. The 25
according to claim 1, wherein a bulkiness of 200-600% is
multifilament yarn showed a tenacity of 7 g/d and an elonga partially imparted to the absorbable multifilament draw-tex
tion of 40%. tured yarn.
The multifilament yarn was plied using Murata 33H (belt 3. The absorbable multifilament draw-textured yarn
type; belt angle 110), while they were twisted on the first according to claim 1 comprising pores in the range of 1-150
roller in the Z-direction, untwisted on the second roller, and 30 um in diameter.
then heat-set at 170° C., thus preparing a draw-textured yarn 4. A cell culture scaffold which allows a cell or body tissue
(DTY) consisting of 224 filaments. The draw-texturing pro to proliferate in the bulky structure of an absorbable multifila
cess was performed at a draw ratio of 1.024 and a linear ment draw-textured yarn according to claim 1.
velocity of 250 m/min. 5. The cell culture scaffold according to claim 4, wherein
Then, the draw-textured yarn made of poly(glycolide-co 35
the absorbable multifilament draw-textured yarn comprises
lactide) was wound on a stretchable rack, and then stretched pores in the range of 1-150 um in diameter.
by 4%, thus preparing a multifilament draw-textured yarn 6. An absorbable multifilament Suture comprising an
having a bulky structure. absorbable multifilament draw-textured yarn according to
claim 1.
The prepared bulky multifilament draw-textured yarn was 7. The absorbable multifilament suture according to claim
separated from the rack, plied two-fold, and then twisted at 40
6, further comprising a Surgical needle coupled with the
about 40 turns/meter, thus preparing a bulky multifilament absorbable multifilament draw-textured yarn.
draw-textured yarn consisting of 448 filaments. 8. The absorbable multifilament suture according to claim
The twisted multifilament draw-textured yarn was cut to a 6, wherein the absorbable multifilament draw-textured yarn
length of 70 cm, and the remainder other than about 5 cm of comprises pores in the range of 1-150 um in diameter.
the central portion of the cut yarn was coated under tension 45
9. An absorbable multifilament draw-textured yarn com
such that the yarn was stretched by about 6%. Then, the prising an absorbable polymer,
coated yarn was dried for about 3 seconds in a convection wherein the absorbable multifilament draw-textured yarn
oven set at 40°C. The coating process was carried out using includes a partial bulky structure having a bulkiness of
a coating solution containing 2 wt % of polycaprolactone in 200-1000%,
methylene chloride. 50
wherein said partial bulky structure is a structure of the
As described above, according to the present invention, an absorbable multifilament draw-textured yarn having
absorbable multifilament draw-textured yarn suitable for pores between said filaments, said pores being greater
medical use is provided by partially imparting a bulkiness of than lum in diameter,
150-1000% to a multifilament draw-textured yarn made of an wherein said partial bulky structure comprises twisted or
absorbable polymer. 55
braided filaments,
Moreover, through the method for manufacturing the wherein said bulkiness is a diameter ratio of a portion of the
absorbable multifilament draw-textured yarn, an multifila absorbable multifilament draw-textured yarn having a
ment yarn having a each diameter of 5-30 um is provided bulky structure relative to a portion of the absorbable
using an absorbable polymer for medical use. multifilament yarn having no bulky structure.
Furthermore, an absorbable multifilament draw-textured
yarn having an ultra-bulky structure is provided. It is useful k k k k k