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Bioactive glass nanoparticles (BGN) are promising materials for a number of biomedical applications. Many parameters related to the synthesis of BGN using sol-gel methods can affect their characteristics. In this study, the influence of timing of calcium nitrate (calcium precursor) addition during processing on BGN characteristics was investigated. The results showed that the addition timing could affect the morphology, dispersity and composition of BGN. With delayed addition of calcium nitrate, larger, more regular and better dispersed BGN could be synthesized while the gap between nominal and actual compositions of BGN was widened. However, the addition timing had no significant influence on structural characteristics, as BGN with different addition-timing of calcium nitrate exhibited similar infrared spectra and amorphous nature. The results also suggested that monodispersed BGN could be synthesized by carefully controlling the addition of calcium nitrate. The synthesized monodispersed BGN could release Si and Ca ions continuously for up to at least 14 days. They also showed in vitro bioactivity and non-cytotoxicity towards rat bone marrow-derived mesenchymal stem cells (rBMSCs). In conclusion, the timing of calcium precursor addition is an essential parameter to be considered when producing BGN which should exhibit monodisperse characteristics for biomedical applications.

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In recent years, porous bioactive glass micro/nanospheres (PBGSs) have emerged as attracting biomaterials in various biomedical applications where such engineered particles provide suitable functions, from tissue engineering to drug delivery....

The development of a guided tissue or bone regeneration (GTR/GBR) membrane with excellent performance has been a major challenge in the biomedical field. The present study was designed to prepare a biomimetic electrospun fish collagen/bioactive glass/chitosan (Col/BG/CS) composite nanofiber membrane and determine its structure, mechanical property, antibacterial activity, and biological effects on human periodontal ligament cells (HPDLCs). The effects of this composite membrane on inducing periodontal tissue regeneration were evaluated using a dog class II furcation defect model. It was found that the composite membrane had a biomimetic structure with good hydrophilicity (the contact angle was 12.83 ± 3°) and a tensile strength of 13.1 ± 0.43 Mpa. Compared to the pure fish collagen membrane, the composite membrane showed some degree of antibacterial activity on Streptococcus mutans. The composite membrane not only enhanced the cell viability and osteogenic gene expression of the HPDLCs, but also promoted the expression of RUNX-2 and OPN protein. Further animal experiments confirmed that the composite membrane was able to promote bone regeneration in the furcation defect of dogs. In conclusion, a biomimetic fish Col/BG/CS composite membrane has been developed in the present study, which can induce tissue regeneration with a certain degree antibacterial activity, providing a basis for potential application as a GTR/GBR membrane.

The development of skin wound dressings with excellent properties has always been an important challenge in the field of biomedicine. In this study, biomimetic electrospun fish collagen/bioactive glass (Col/BG) nanofibers were prepared. Their structure, tensile strength, antibacterial activity and biological effects on human keratinocytes, human dermal fibroblasts and human vascular endothelial cells were investigated. Furthermore, the Sprague Dawley rat skin defect model was used to validate their effect on wound healing. The results showed that compared with pure fish collagen nanofibers, the tensile strength of the Col/BG nanofibers increased to 21.87±0.21 Mpa, with a certain degree of antibacterial activity against Staphylococcus aureus . It was also found that the Col/BG nanofibers promoted the adhesion, proliferation and migration of human keratinocytes. Col/BG nanofibers induced the secretion of type one collagen and vascular endothelial growth factor by human dermal fibroblasts, which further stimulated the proliferation of human vascular endothelial cells. Animal experimentation indicated that the Col/BG nanofibers could accelerate rat skin wound healing. This study developed a type of multifunctional and biomimetic fish Col/BG nanofibers, which had the ability to induce skin regeneration with adequate tensile strength and antibacterial activity. The Col/BG nanofibers are also easily available and inexpensive, providing the possibility for using as a functional skin wound dressing.

The development of nanomaterials for stable, controlled delivery of drugs and efficient suppression of tumor growth with desirable biosafety remains challenging in the nano-biomedical field. In this study, we prepared and optimized mesoporous bioactive glass (MBG) nanospheres to establish a functional drug delivery system and analyzed the effect of the dendritic mesoporous structure on drug loading and release. We then utilized an in vitro model to examine the biological effects of dendritic MBG nanospheres on normal and tumor cells and studied the molecular mechanism underlying specific tumor suppression by MBG nanospheres. Finally, we investigated the combinational effect of MBG nanospheres and a cancer therapeutic drug with an in vivo tumor xenograft model. Our results show that the dendritic MBG nanospheres have been successfully synthesized by optimizing calcium: silicon ratio. MBG nanospheres exhibit a dendritic mesoporous structure with a large specific surface area, demonstrate high drug loading efficiency, and release drugs in a controlled fashion to effectively prolong drug half-life. Ca in nanospheres activates transient receptor potential channels and calcium-sensing receptor on tumor cells, mediates calcium influx, and directly regulates the calpain-1-Bcl-2-caspase-3 signaling pathway to specifically suppress tumor growth without affecting normal cells. In addition, dendritic MBG nanospheres synergize with cancer drugs to improve antitumor efficacy and reduce systemic toxicity. Dendritic MBG nanospheres with antitumor activity and controlled drug release have been successfully achieved and the underlying molecular mechanism was elucidated, paving the way for translational application.

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