Search

Biodegradable elastomers with good biocompatibility have attracted much attention in biomedical diagnosis/therapy/regenerative medicine, as bioresorbable electronics and implanted devices. The bacterial infection, tissue toxicity, serious inflammatory response and tumorigenesis for implanted devices are still the important obstacles for their biomedical applications. Herein, we reported biodegradable ultralong copper sulfide nanowire-reinforced poly(citrates-siloxane) (PCS-CSNW) nanocomposites elastomers with inherent multifunctional properties for potential biomedical applications. The structure-homogeneous nanocomposites were formed through the hydrophobic-hydrophobic interaction between the oleylamine capped CSNW and polymer chain. PCS-CSNW showed controlled elastomeric mechanical behavior, tunable electronic conductivity and broad-spectrum antibacterial activity against gram-positive/gram-negative bacterium in vitro/in vivo. PCS-CSNW also exhibited tailored photoluminescent property and strong near-infrared (NIR) photothermal capacity which enabled the high-resolution in vivo thermal imaging and biodegradation tracking. Additionally, PCS-CSNW also demonstrated good cell biocompatibility and decreased inflammatory reaction in vivo. The cancer cells on PCS-CSNW nanocomposites were efficiently killed through a selective NIR-induced photothermal therapy. This work may provide a new strategy to design next-regeneration smart implanted devices for biomedical applications in bioresorbable electronics, tissue engineering and regenerative medicine., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

It remains a challenge to develop electroactive and elastic biomaterials to mimic the elasticity of soft tissue and to regulate the cell behavior during tissue regeneration. We designed and synthesized a series of novel electroactive and biodegradable polyurethane-urea (PUU) copolymers with elastomeric property by combining the properties of polyurethanes and conducting polymers. The electroactive PUU copolymers were synthesized from amine capped aniline trimer (ACAT), dimethylol propionic acid (DMPA), polylactide, and hexamethylene diisocyanate. The electroactivity of the PUU copolymers were studied by UV-vis spectroscopy and cyclic voltammetry. Elasticity and Young's modulus were tailored by the polylactide segment length and ACAT content. Hydrophilicity of the copolymer films was tuned by changing DMPA content and doping of the copolymer. Cytotoxicity of the PUU copolymers was evaluated by mouse C2C12 myoblast cells. The myogenic differentiation of C2C12 myoblasts on copolymer films was also studied by analyzing the morphology of myotubes and relative gene expression during myogenic differentiation. The chemical structure, thermal properties, surface morphology, and processability of the PUU copolymers were characterized by NMR, FT-IR, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and solubility testing, respectively. Those biodegradable electroactive elastic PUU copolymers are promising materials for repair of soft tissues such as skeletal muscle, cardiac muscle, and nerve.

Multi-armed biodegradable polymers have attracted much attention in biomedical applications, due to their special structure and properties. However, multi-armed organic-inorganic hybrids with high mechanical properties and biomineralization activity have not been reported yet. Here, star-shaped poly-L-lactide-poly (ethylene glycol)-polyhedral oligomeric silsesquioxane (SPPS) hybrid membranes are fabricated for the first time for guiding bone regeneration applications by a photo-crosslinking method using inositol as a core. SPPS demonstrates tunable mechanical properties (5.8 ± 0.2 ∼ 130 ± 23 MPa in tensile modulus, 30 ± 6% ∼ 144 ± 13% in elongation, beyond 90% recovery), biodegradation, biomineralization activity and good osteoblast biocompatibility. These results suggest that our hybrids membrane may have promising applications in guiding bone regeneration., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Biodegradable and star-shaped polymers with highly tunable structure and properties have attracted much attention in recent years for potential biomedical applications, due to their special structure. Here, inositol-based star-shaped poly-L-lactide-poly(ethylene glycol) (INO-PLLA-PEG) biomedical polymer implants were for the first time synthesized by a facile photo-crosslinking method. This biomaterials show controlled elastomeric mechanical properties (~18 MPa in tensile strength, ~200 MPa in modulus, ~200% in elongation), biodegradability and osteoblasts biocompatibility. These results make INO-PLLA-PEG implants highly promising for bone tissue regeneration and drug delivery applications., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Artificial muscle-like biomaterials have gained tremendous interests owing to their broad applications in regenerative medicine, wearable devices, bioelectronics and artificial intelligence. Unfortunately, key challenges are still existed for current materials, including biomimetic viscoelasticity, biocompatibility and biodegradation, multifunctionality. Herein, for the first time, we develop highly elastomeric, conductive and biodegradable poly (citric acid-octanediol-polyethylene glycol)(PCE)-graphene (PCEG) nanocomposites, and demonstrate their applications in myogenic differentiation and guiding skeletal muscle tissue regeneration. In PCEG nanocomposites, PCE provides the biomimetic elastomeric behavior, and the addition of reduced graphene oxide (RGO) endows the enhanced mechanical strength and conductivity. The highly elastomeric behavior, significantly enhanced modulus (400%–800%), strength (200%–300%) of PCEG nanocomposites with controlled biodegradability and electrochemical conductivity were achieved. The myoblasts proliferation and myogenic differentiation were significantly improved by PCEG nanocomposite. Significantly high in vivo biocompatibility of PCEG nanocomposites was observed when implanted in the subcutaneous tissue for 4 weeks in rats. PCEG nanocomposites could significantly enhance the muscle fibers and blood vessels formation in vivo in a skeletal muscle lesion model of rat. This study may provide a novel strategy to develop multifunctional elastomeric nanocomposites with high biocompatibility for potential soft tissue regeneration and stretchable bioelectronic devices. [ABSTRACT FROM AUTHOR]

Biodegradable biomaterials with intrinsically multifunctional properties such as high strength, photoluminescent ability (bioimaging monitoring), and antimicrobial activity (anti-infection), as well as high osteoblastic differentiation ability, play a critical role in successful bone tissue regeneration. However, fabricating a biomaterial containing all these functions is still a challenge. Here, urethane cross-linked intrinsically multifunctional silica-poly(citrate) (CMSPC)-based hybrid elastomers are developed by first one-step polymerization and further chemical crosslinked using isocyanate. CMSPC hybrid elastomers demonstrate a high modulus of 976 ± 15 MPa, which is superior compared with most conventional poly(citrate)-based elastomers. Hybrid elastomers show strong and stable intrinsic photoluminescent ability (emission 400-600 nm) due to the incorporation of silica phase. All elastomers exhibit high inherent antibacterial properties against Staphylococcus aureus. In addition, CMSPC hybrid elastomers significantly enhance the proliferation and metabolic activity of osteoblasts (MC3T3-E1). CMSPC hybrid elastomers significantly promote the osteogenic differentiation of MC3T3-E1 by improving alkaline phosphatase activity and calcium biomineralization deposits, as well as expressions of osteoblastic genes. These hybrid elastomers also show a minimal inflammatory response indicated by subcutaneous transplantation in vivo. These optimized structure and multifunctional properties make this hybrid elastomer highly promising for bone tissue regeneration and antiinfection and bioimaging applications. [ABSTRACT FROM AUTHOR]