scholarly journals Preparation and In Vitro Behavior of a Poly(lactic acid)-Fiber/Hydroxyapatite Composite Sheet

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Yasuhiro Tanimoto ◽  
Norihiro Nishiyama

This paper describes the processing and in vitro behavior of a poly(lactic acid) (PLA)-fiber/hydroxyapatite (HA) composite sheet consisting of a knitted PLA-fiber sheet and HA powder for bone tissue engineering. Type I collagen was used as a binding agent to combine the PLA fibers and the HA powder. Precipitate formation in Hanks' balanced salt (HBS) solution was monitored to evaluate the in vitro apatite formation ability of the PLA-fiber/HA composite sheet. Precipitate formation was observed on the surface of the PLA-fiber/HA composite sheet after immersion in HBS solution for only 1 day, while no precipitate formation was observed on the PLA-fiber sheet without HA as a control. In conclusion, a PLA-fiber/HA composite sheet for use as a scaffold was successfully prepared. Within the limitations of this investigation, we confirmed that the PLA-fiber/HA composite sheet has a high apatite formation activity compared with the PLA-fiber sheet and represents a promising material for use as a scaffold.

2015 ◽  
Vol 6 (3) ◽  
pp. 667-686 ◽  
Author(s):  
Xiangchen Qiao ◽  
Stephen Russell ◽  
Xuebin Yang ◽  
Giuseppe Tronci ◽  
David Wood

2002 ◽  
Vol 735 ◽  
Author(s):  
Victor J. Chen ◽  
Peter X. Ma

ABSTRACTHighly porous nano-fibrous poly(L-lactic acid) (PLLA) scaffolds were prepared and incubated in a simulated body fluid which resulted in the in situ formation of partially carbonated bone-like apatite. The macroporous interconnected architecture was created with a three-dimensional mold of thermally-bonded paraffin microspheres. PLLA solution was cast over the paraffin mold and was thermally induced to phase separate to form nano-scale fibers that mimic the fibrous structures of type I collagen. To potentially improve the osteoconductivity of these scaffolds, they were incubated in a buffered simulated body fluid at 37°C for certain periods of time to allow for apatite formation. It was seen that over time, the apatite particles increased in size. In addition, the growth of apatite particles on the nano-fibrous scaffolds was compared with the growth of particles on similar porous PLLA scaffolds with a solid-walled (not nano-fibrous) morphology. It was seen that the initial number of particles per unit area and the overall increase in mass of the scaffolds were significantly higher in the nano-fibrous scaffolds than in the solid-walled scaffolds. These novel scaffolds have well-defined architectures at three different size scales: (i) interconnected spherical pores ∼250–400 m in diameter; (ii) fibrous collagen-like matrix with fibers 50–500 nm in diameter; and (iii) carbonated bone-like apatite particles at the nanometer to micrometer scales; the scaffolds may serve as superior support for bone tissue regeneration.


Author(s):  
Arthur J. Wasserman ◽  
Kathy C. Kloos ◽  
David E. Birk

Type I collagen is the predominant collagen in the cornea with type V collagen being a quantitatively minor component. However, the content of type V collagen (10-20%) in the cornea is high when compared to other tissues containing predominantly type I collagen. The corneal stroma has a homogeneous distribution of these two collagens, however, immunochemical localization of type V collagen requires the disruption of type I collagen structure. This indicates that these collagens may be arranged as heterpolymeric fibrils. This arrangement may be responsible for the control of fibril diameter necessary for corneal transparency. The purpose of this work is to study the in vitro assembly of collagen type V and to determine whether the interactions of these collagens influence fibril morphology.


2021 ◽  
Vol 10 (14) ◽  
pp. 3141
Author(s):  
Hyerin Jung ◽  
Yeri Alice Rim ◽  
Narae Park ◽  
Yoojun Nam ◽  
Ji Hyeon Ju

Osteogenesis imperfecta (OI) is a genetic disease characterized by bone fragility and repeated fractures. The bone fragility associated with OI is caused by a defect in collagen formation due to mutation of COL1A1 or COL1A2. Current strategies for treating OI are not curative. In this study, we generated induced pluripotent stem cells (iPSCs) from OI patient-derived blood cells harboring a mutation in the COL1A1 gene. Osteoblast (OB) differentiated from OI-iPSCs showed abnormally decreased levels of type I collagen and osteogenic differentiation ability. Gene correction of the COL1A1 gene using CRISPR/Cas9 recovered the decreased type I collagen expression in OBs differentiated from OI-iPSCs. The osteogenic potential of OI-iPSCs was also recovered by the gene correction. This study suggests a new possibility of treatment and in vitro disease modeling using patient-derived iPSCs and gene editing with CRISPR/Cas9.


Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 29
Author(s):  
Seung Kyun Yoon ◽  
Jin Ho Yang ◽  
Hyun Tae Lim ◽  
Young-Wook Chang ◽  
Muhammad Ayyoob ◽  
...  

Herein, spinal fixation implants were constructed using degradable polymeric materials such as PGA–PLA block copolymers (poly(glycolic acid-b-lactic acid)). These materials were reinforced by blending with HA-g-PLA (hydroxyapatite-graft-poly lactic acid) and PGA fiber before being tested to confirm its biocompatibility via in vitro (MTT assay) and in vivo animal experiments (i.e., skin sensitization, intradermal intracutaneous reaction, and in vivo degradation tests). Every specimen exhibited suitable biocompatibility and biodegradability for use as resorbable spinal fixation materials.


2021 ◽  
Vol 19 ◽  
pp. 228080002198969
Author(s):  
Min-Xia Zhang ◽  
Wan-Yi Zhao ◽  
Qing-Qing Fang ◽  
Xiao-Feng Wang ◽  
Chun-Ye Chen ◽  
...  

The present study was designed to fabricate a new chitosan-collagen sponge (CCS) for potential wound dressing applications. CCS was fabricated by a 3.0% chitosan mixture with a 1.0% type I collagen (7:3(w/w)) through freeze-drying. Then the dressing was prepared to evaluate its properties through a series of tests. The new-made dressing demonstrated its safety toward NIH3T3 cells. Furthermore, the CCS showed the significant surround inhibition zone than empty controls inoculated by E. coli and S. aureus. Moreover, the moisture rates of CCS were increased more rapidly than the collagen and blank sponge groups. The results revealed that the CCS had the characteristics of nontoxicity, biocompatibility, good antibacterial activity, and water retention. We used a full-thickness excisional wound healing model to evaluate the in vivo efficacy of the new dressing. The results showed remarkable healing at 14th day post-operation compared with injuries treated with collagen only as a negative control in addition to chitosan only. Our results suggest that the chitosan-collagen wound dressing were identified as a new promising candidate for further wound application.


1991 ◽  
Vol 274 (2) ◽  
pp. 615-617 ◽  
Author(s):  
P Kern ◽  
M Menasche ◽  
L Robert

The biosynthesis of type I, type V and type VI collagens was studied by incubation of calf corneas in vitro with [3H]proline as a marker. Pepsin-solubilized collagen types were isolated by salt fractionation and quantified by SDS/PAGE. Expressed as proportions of the total hydroxyproline solubilized, corneal stroma comprised 75% type I, 8% type V and 17% type VI collagen. The rates of [3H]proline incorporation, linear up to 24 h for each collagen type, were highest for type VI collagen and lowest for type I collagen. From pulse-chase experiments, the calculated apparent half-lives for types I, V and VI collagens were 36 h, 10 h and 6 h respectively.


Author(s):  
Harrison T. Pajovich ◽  
Alexandra M. Brown ◽  
Andrew M. Smith ◽  
Sara K. Hurley ◽  
Jessica R. Dorilio ◽  
...  

In this work, for the first time, chlorogenic acid, a natural phytochemical, was conjugated to a lactoferrin derived antimicrobial peptide sequence RRWQWRMKKLG to develop a self-assembled template. To mimic the components of extracellular matrix, we then incorporated Type I Collagen, followed by a sequence of aggrecan peptide (ATEGQVRVNSIYQDKVSL) onto the self-assembled templates for potential applications in ligament tissue regeneration. Mechanical properties and surface roughness were studied and the scaffolds displayed a Young’s Modulus of 169 MP and an average roughness of 72 nm respectively. Thermal phase changes were studied by DSC analysis. Results showed short endothermic peaks due to water loss and an exothermic peak due to crystallization of the scaffold caused by rearrangement of the components. Biodegradability studies indicated a percent weight loss of 27.5 % over a period of 37 days. Furthermore, the scaffolds were found to adhere to fibroblasts, the main cellular component of ligament tissue. The scaffolds promoted cell proliferation and displayed actin stress fibers indicative of cell motility and attachment. Collagen and proteoglycan synthesis were also promoted, demonstrating increased expression and deposition of collagen and proteoglycans. Additionally, the scaffolds exhibited antimicrobial activity against Staphylococcus epidermis bacteria, which is beneficial for minimizing biofilm formation if potentially used as implants. Thus, we have developed a novel biocomposite that may open new avenues to enhance ligament tissue regeneration.


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