Silk-Inspired ß-Peptide Materials Resist Fouling and the Foreign-Body Response.

The functions of implants like medical devices are often compromised by the host's foreign-body response (FBR). Herein, we report the development of low-FBR materials inspired by serine-rich sericin from silk. Poly-ß-homoserine (ß-HS) materials consist of the hydrophilic unnatural amino acid ß-homoserine. Self-assembled monolayers (SAMs) of ß-HS resist adsorption by diverse proteins, as well as adhesion by cells, platelets, and diverse microbes. Experiments lasting up to 3 months revealed that, while implantation with control PEG hydrogels induced obvious inflammatory responses, collagen encapsulation, and macrophage accumulation, these responses were minimal with ß-HS hydrogels. Strikingly, the ß-HS hydrogels induce angiogenesis in implant-adjacent tissues. Molecular dynamics simulations indicated that the low FBR performance of ß-HS results from what we term "dual hydrogen bonding hydration", wherein both the backbone amide groups and the sidechain hydroxyl groups of ß-HS undergo hydration.

Influences of sodium tantalite submicro-particles in polyetheretherketone based composites on behaviors of rBMSCs/HGE-1 cells for dental application.

Dental implanted materials require excellent mechanical properties, biocompatibility as well as integration with bone tissue and gingival tissue to achieve early loading and long-term stability. In this study, cubic shape sodium tantalite (ST) submicro-particles with the size of around 180 nm were synthesized by a hydrothermal method, and ST/polyetheretherketone (PEEK) composites (TPC) with ST content of 20 w% (TPC20) and 40 w% (TPC40) were prepared by melting blend. The results showed that the compressive strength, thermal properties, surface roughness, hydrophilicity and surface energy as well as adsorption of proteins on TPC40 were also significantly enhanced compared with TPC20 and PEEK. Moreover, the responses (adhesion and proliferation as well as differentiation) of rat bone marrow mesenchymal stem cells (rBMSCs), and responses (adhesion, and proliferation) of human gingival epithelial (HGE-1) cells to TPC40 were significantly promoted compared with TPC20 and PEEK. The results demonstrated that ST content in TPC had remarkable effects on the surface properties, which played key roles in stimulating the responses of both rBMSCs and HGE-1 cells. TPC40 with increased surface properties and excellent cytocompatibility might have great potential as an implanted material for dental application.

Improvement of rBMSCs Responses to Poly(propylene carbonate) Based Biomaterial through Incorporation of Nanolaponite and Surface Treatment Using Sodium Hydroxide.

Poly(propylene carbonate) (PPC) has aroused extensive attention in the biomaterial field because of its excellent biocompatibility and appropriate degradability, but surface hydrophobicity and bioinertness limit its applications for bone repair and tissue engineering. In this study, a bioactive PPC/laponite (LAP) nanocomposite (PL) was prepared by a melt-blending method, and a microporous surface on PPC and PL (PT and PLT) was created by sodium hydroxide (NaOH) treatment. The results demonstrated that the surface roughness, hydrophilicity, surface energy, and degradability as well as protein adsorption of PLT were obviously improved compared with PPC. Moreover, the degradability of PLT was remarkably enhanced with a slight increase of pH values in Tris-HCl solution. Furthermore, adhesion and proliferation as well as osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) to PLT were significantly promoted compared with PPC. The results suggested that incorporating LAP into PPC obviously improved the surface performance of PL (with nanotopography), and surface treatment with NaOH further enhanced surface properties of PLT (with micronanotopography and hydrophilic groups), which significantly promoted responses of rBMSCs. In short, PLT displayed excellent cytocompatibility, which would have great potential for bone regeneration.

Lithium doped silica nanospheres/poly(dopamine) composite coating on polyetheretherketone to stimulate cell responses, improve bone formation and osseointegration.

Osseointegration is crucial for early fixation as well as long-term success of orthopedic implants. Bioactive composite containing lithium doping silica nanospheres (LSNs) and poly(dopamine) (PDA) were coated on polyetheretherketone (PK) surface (LPPK), and effects of the LSNs/PDA composite (LPC) coating on the biological properties of LPPK were assessed both in vitro and in vivo. Results showed that LPPK with improved bioactivity remarkably promoted apatite mineralization in simulated body fluid (SBF) compared with PDA coated on PK (PPK) and PK. Moreover, the LPPK remarkably stimulated rat bone marrow stromal cells (rBMSCs) responses compared with PPK and PK. Furthermore, the LPPK significantly promoted bone tissues responses in vivo compared with PPK and PK. It could be suggested that the improvements of cells and bone tissues responses were attributed to the surface characteristics of the bioactive LPC coating on LPPK. The LPPK would be a great candidate for orthopedic and dental applications.

Tissue engineering scaffolds of mesoporous magnesium silicate and poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) composite.

Mesoporous magnesium silicate (m-MS) and poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL) composite scaffolds were fabricated by solvent-casting and particulate leaching method. The results suggested that the incorporation of m-MS into PCL-PEG-PCL could significantly improve the water adsorption of the m-MS/PCL-PEG-PCL composite (m-MPC) scaffolds. The in vitro degradation behavior of m-MPC scaffolds were determined by testing weight loss of the scaffolds after soaking into phosphate buffered saline (PBS), and the result showed that the degradation of m-MPC scaffolds was obviously enhanced by addition of m-MS into PCL-PEG-PCL after soaking for 10 weeks. Proliferation of MG63 cells on m-MPC was significantly higher than MPC scaffolds at 4 and 7 days. ALP activity on the m-MPC was obviously higher than MPC scaffolds at 7 days, revealing that m-MPC could promote cell differentiation. Histological evaluation showed that the introduction of m-MS into PCL-PEG-PCL enhanced the efficiency of new bone formation when the m-MPC scaffolds implanted into bone defect of rabbits. The results suggested that the inorganic/organic composite of m-MS and PCL-PEG-PCL scaffolds exhibited good biocompatibility, degradability and osteogenesis.