Changchun Zhou

A review of protein adsorption on bioceramics

Bioceramics, because of its excellent biocompatible and mechanical properties, has always been considered as the most promising materials for hard tissue repair. It is well know that an appropriate cellular response to bioceramics surfaces is essential for tissue regeneration and integration. As the in vivo implants, the implanted bioceramics are immediately coated with proteins from blood and body fluids, and it is through this coated layer that cells sense and respond to foreign implants. Hence, the adsorption of proteins is critical within the sequence of biological activities. However, the biological mechanisms of the interactions of bioceramics and proteins are still not well understood. In this review, we will recapitulate the recent studies on the bioceramic–protein interactions.

Localized multidrug co-delivery by injectable self-crosslinking hydrogel for synergistic combinational chemotherapy

Significant progress has been made in the use of injectable hydrogels as drug carrier systems to treat cancers by the peritumoral-localized co-delivery of multiple drugs with different therapeutic mechanisms. In this study, a novel, injectable self-crosslinking HA-SH hydrogel was able to concurrently encapsulate multiple drugs (sorafenib, doxorubicin, and metformin) to enhance chemotherapy efficacy. The hydrogel was relatively stable under physiological conditions and could quickly and directly release the loaded drugs to the tumor site in a reductive tumor microenvironment. The in vitro antitumor activity and cell-apoptosis assay demonstrated that the hydrogel loaded with multiple drugs (Gel + DS or Gel + DSM) showed obvious synergistic effects against breast cancer cells. The combinational chemotherapy enhanced the sensitivities of tumor cells and promoted tumor cell apoptosis after peritumoral administration. Compared with the single drug-loaded hydrogel, the hydrogel co-loaded with multiple drugs (Gel + DSM) showed the best tumor growth inhibition. Moreover, the monitoring of mice weight and ex vivo histological analysis of the main organs indicated that localized treatment with the hydrogel co-loaded with multiple drugs (Gel + DSM) obviously relieved the systemic toxicity and showed promise for inhibiting tumor metastasis, suggesting the superiority and potential application prospects of the injectable, self-crosslinking hydrogel co-loaded with multiple drugs.

Bio-Functional Design, Application and Trends in Metallic Biomaterials

Introduction of metals as biomaterials has been known for a long time. In the early development, sufficient strength and suitable mechanical properties were the main considerations for metal implants. With the development of new generations of biomaterials, the concepts of bioactive and biodegradable materials were proposed. Biological function design is very import for metal implants in biomedical applications. Three crucial design criteria are summarized for developing metal implants: (1) mechanical properties that mimic the host tissues; (2) sufficient bioactivities to form bio-bonding between implants and surrounding tissues; and (3) a degradation rate that matches tissue regeneration and biodegradability. This article reviews the development of metal implants and their applications in biomedical engineering. Development trends and future perspectives of metallic biomaterials are also discussed.

Biological effects of apatite nanoparticle-constructed ceramic surfaces in regulating behaviours of mesenchymal stem cells

Although calcium phosphate (CaP) ceramics have been originally defined as bioactive materials because a biologically active hydroxycarbonate apatite (HCA) layer can form on their surfaces, the biological effects of the as-grown HCA layers are far from understood. In particular, it is unclear whether the as-grown HCA nanotopography can mediate the osteogenic commitment of mesenchymal stem cells (MSCs). In this study, a systematic investigation was performed to investigate the formation and biological effects of HCA nanotopography on CaP ceramic surfaces. Experiments demonstrate that the hydroxyapatite phase-containing CaP ceramics tend to grow HCA nanoparticle-constructed nanotopography, which can mediate bone marrow MSCs to condensate and spontaneously differentiate toward osteogenic lineage. In addition, the biological evolution of MSCs adhered on such nanotopography is similar to intramembranous ossification. Our findings provide support for applications of wurtzite phase-containing CaP ceramics in regenerative medicine for hard tissues.