The functional reconstruction of bone defects caused by trauma, infection, surgical resection and degenerative diseases poses substantial clinical challenges. Bone tissue engineering (BTE) holds immense potential for treating bone defects while avoiding complications commonly associated with conventional autografts, allografts and internal fixation. Bioactive hydrogels with exceptional drug delivery capabilities, excellent biocompatibility and tunable physicochemical properties have emerged as promising biomaterial scaffolds for BTE. This review provides a comprehensive overview of recent advancements in bioactive hydrogel–based strategies for BTE applications. An initial introduction to bone physiology is followed by a critical discussion of the design considerations for hydrogel platforms, specifically biomaterial selection, innovative crosslinking mechanisms and bioactive functionalization. Furthermore, hydrogel engineering for the controlled delivery of bioactive cargo is critically examined, with an emphasis on spatiotemporally programmable release behaviors that coordinate osteogenesis, angiogenesis and immunomodulation. Finally, key translational challenges are discussed, and the emerging role of artificial intelligence–assisted design is explored as a transformative approach for facilitating the clinical translation of next-generation bioactive hydrogels for BTE.
Chongzheng Yan, Yuxue Pan, Yu Tian et al.· Asian Journal of Pharmaceuti...· 0 citations
The development of proteolysis-targeting chimeras (PROTACs) represents a promising strategy for targeted protein degradation in cancer therapy. However, the limited tumor-specific targeting and the inherent unfavorable physicochemical properties of PROTACs lead to insufficient cellular uptake and suboptimal antitumor immune responses. Herein, as a proof of concept, we developed an oncolytic virus-PROTAC conjugate (BPAD) by efficiently coupling bromodomain-containing protein 4 (BRD4)-targeting PROTACs with oncolytic viruses (OVs). In BPAD, the potent and highly selective infection of OVs to tumor cells enhances both cellular uptake and tumor-selective delivery of PROTACs, resulting in a 640-fold increase in the protein degradation efficiency. Moreover, prior to OV-induced tumor lysis, the preferential replication of OVs within tumor cells, combined with BRD4 degradation, promotes the secretion of type I interferons and facilitates dendritic cell maturation. Overall, the BPAD strategy enables the development of biologically derived macromolecular PROTAC conjugates, thereby enhancing the clinical translation potential of diverse PROTACs.