Heparin‐conjugated star‐shaped PLA for improved biocompatibility

Abstract

Star-shaped PLA-heparin (sPLA-Hep) was prepared by coupling heparin to the star-shaped PLA (sPLA) reaction using carbonyldiimidazole (CDI) chemistry. Hydroxyl groups of sPLA were activated by CDI for the reaction with the remained amino-terminal groups of heparin. The surface heparin content of sPLA-Hep was measured to be 1.43 microg/cm(2). sPLA-Hep-coated surface has shown higher hydrophilicity than control surface. The clotting time of sPLA-Hep measured by activated partial thromboplastin time (APTT) was significantly prolonged when compared with sPLA and linear PLA-Hep. sPLA-Hep surface demonstrated lower protein adsorption and platelet adhesion than control sPLA surface. In addition, fibroblast culture on the sPLA-Hep surface showed the enhanced cell spreading area compared with the sPLA surface. Obtained results suggest that the incorporation of heparin to sPLA is effective in curtailing the surface induced-thrombosis and in manipulating the cell interaction. sPLA-Hep could be applied as blood/tissue compatible biodegradable materials for implantable medical devices and tissue engineering.

Stem cell recruitment, angiogenesis, and tissue regeneration in substance P‐conjugated poly(l‐lactide‐co‐ɛ‐caprolactone) nonwoven meshes

“…25 With MT staining, connective tissues were stained blue, nuclei were stained dark red/purple, and cytoplasm was stained red/pink. The stained sections were observed by light microscopy (Eclipse TE2000U;…”

“…1A). 25 The representative procedure for the conjugation of the amino (ε-NH 2 ) groups of SP with star-shaped P(LA-co-CL) copolymer is as follows: star-shaped P(LA-co-CL) (M n ~ 67382, PDI = 1.80, 4.48 × 10 -5 moles)…”

“…The sterilized meshes were coated with collagen solution (1 mg/mL in 1 % acetic acid) and incubated at 4 ºC overnight. 25 To remove residual solution, collagen-coated meshes were washed three times with PBS. All animals were treated in accordance with the recommendations …”

“…[24][25] The structural characteristics of P(LA-co-CL)-SP were analyzed, and electrospun nanofibers were prepared by mixing appropriate ratios of P(LA-co-CL) and P(LA-co-CL)-SP copolymers. We have determined the effect of SP-functionalized P(LA-co-CL) copolymers on: (1) sustained release of SP in vitro and in vivo, (2) the mobilization of stem cells in vitro and in vivo, (3) the bioactivity following subcutaneous implantation, and (4) angiogenesis in vivo.…”

Glucose Sensor Membranes for Mitigating the Foreign Body Response

“…13,14 Coating a sensor with biomolecules is one passive approach used to circumvent the FBR since certain materials may allow the implant to appear less foreign to the host. A wide range of biomolecules have been used to interact with surrounding tissue and mitigate the FBR, including collagen, 15,16 chitosan, 17 cellulose, 18,19 heparin, 20 and dextran. 21,22 While these may prove beneficial for in vivo use, they are capable of eliciting an immunogenic response and are often undesirably biodegradable.…”