Biomedical subjects

Shanfeng Wang

Publications and source records attributed to Shanfeng Wang.

3 recordsLinked to original sources

PubMed2006

Bone-tissue-engineering material poly(propylene fumarate): correlation between molecular weight, chain dimensions, and physical properties.

Poly(propylene fumarate) (PPF) is an important biodegradable and cross-linkable polymer designed for bone-tissue-engineering applications. For the first time we report the extensive characterization of this biomaterial including molecular weight dependences of physical properties such as glass transition temperature Tg, thermal degradation temperature Td, density rho, melt viscosity eta0, hydrodynamic radius RH, and intrinsic viscosity [eta]. The temperature dependence of eta0 changes progressively with molecular weight, whereas it can be unified when the temperature is normalized to Tg. The plateau modulus and entanglement molecular weight Me have been obtained from the rheological master curves. A variety of chain microstructure parameters such as the Mark-Houwink-Sakurada constants K and alpha, characteristic ratio Cinfinity, unperturbed chain dimension r0(2)/M, packing lengthp, Kuhn length b, and tube diameter a have been deduced. Further correlation between the microstructure and macroscopic physical properties has been discussed in light of recent progress in polymer dynamics to supply a better understanding about this unsaturated polyester to advance its biomedical uses. The molecular weight dependence of Tg for six polymer species including PPF has been summarized to support that Me is irrelevant for the finite length effect on the glass transition, whereas surprisingly these polymers can be divided into two groups when their normalized Tg is plotted simply against Mw to indicate the deciding roles of inherent chain properties such as chain fragility, intermolecular cooperativity, and chain end mobility.

Bone Substitutes↗

PubMed2005

Synthesis and characterizations of biodegradable and crosslinkable poly(epsilon-caprolactone fumarate), poly(ethylene glycol fumarate), and their amphiphilic copolymer.

A series of self-crosslinkable and biodegradable polymers, poly(caprolactone fumarate) (PCLF), poly(ethylene glycol fumarate) (PEGF), and their copolymer PEGF-co-PCLF, has been developed for tissue engineering applications using a novel synthesis method. The current method employs potassium carbonate (K2CO3), other than the previously reported triethylamine, as the proton scavenger. The new synthetic route is more convenient and less time-consuming to carry out, and the synthesized polymers have a much lighter color, which renders them more suitable for self-crosslinking via photo-initiation. This group of polymers are essentially copolymers of fumaryl chloride, which contains double bonds for in situ crosslinking, with poly(epsilon-caprolactone) (PCL) or/and poly(ethylene glycol) (PEG) that has a flexible chain to facilitate self-crosslinking. Both PCLF and PEGF, and their amphiphilic copolymer PEGF-co-PCLF could be self-crosslinked or photocrosslinked to produce scaffolds without the use of a crosslinking agent. Our results suggest that these polymers are potentially useful as injectable, self-crosslinkable, and photo-crosslinkable materials for diverse tissue engineering applications.

Biocompatible Materials↗

PubMedDate not supplied

Synthesis, material properties, and biocompatibility of a novel self-cross-linkable poly(caprolactone fumarate) as an injectable tissue engineering scaffold.

A novel self-cross-linkable and biodegradable macromer, poly(caprolactone fumarate) (PCLF), has been developed for guided bone regeneration. This macromer is a copolymer of fumaryl chloride, which contains double bonds for in-situ cross-linking, and poly(epsilon-caprolactone), which has a flexible chain to facilitate self-cross-linkability. PCLF was characterized with Fourier transform infrared spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopy, and gel permeation chromatography. Porous scaffolds were fabricated with sodium chloride particles as the porogen and a chemical initiation system. The PCLF scaffolds were characterized with scanning electron microscopy and micro-computed-tomography. The cytotoxicity and in vivo biocompatibility of PCLF were also assessed. Our results suggest that this novel copolymer, PCLF, is an injectable, self-cross-linkable, and biocompatible macromer that may be potentially used as a scaffold for tissue engineering applications.

Animals↗