Recent Strategies and Advances in Hydrogel‑Based Delivery Platforms for Bone Regeneration

Bioactive molecules have shown great promise for effectively regulating various bone formation processes,rendering them attractive therapeutics for bone regeneration.However,the widespread application of bioactive molecules is limited by their low accumulation and short half-lives in vivo.Hydrogels have emerged as ideal carriers to address these challenges,offering the potential to prolong retention times at lesion sites,extend half-lives in vivo and mitigate side effects,avoid burst release,and promote adsorption under physiological conditions.This review systematically summarizes the recent advances in the development of bioactive molecule-loaded hydrogels for bone regeneration,encompassing applications in cranial defect repair,femoral defect repair,periodontal bone regeneration,and bone regeneration with underlying diseases.Additionally,this review discusses the current strategies aimed at improving the release profiles of bioactive molecules through stimuli-responsive delivery,carrier-assisted delivery,and sequential delivery.Finally,this review elucidates the existing challenges and future directions of hydrogel encapsulated bioactive molecules in the field of bone regeneration.

Recent Advances in Bronchopulmonary Dysplasia Protection and Therapy

For preterm infants, bronchopulmonary dysplasia (BPD) is usually caused by abnormal lung development due to various factors during prenatal and postnatal process. One of the reasons for death and bad prognosis of preterm infants is to have BPD. Up to now, there are no unified strategies or drugs to treat BPD. In clinical, many intervention treatments have been applied to achieve BPD therapy, mainly including preterm protection, protective ventilation strategies, and delivery of corticosteroids, pulmonary vasodilators, and antioxidants. This review summarizes the current advances in BPD protection and treatment, and notes that gut microbiota and mesenchymal stem cells (MSCs) can be the promising strategy for protecting and treating BPD in the future.

Antibacterial and antioxidant bifunctional hydrogel based on hyaluronic acid complex MoS_(2)-dithiothreitol nanozyme for treatment of infected wounds

Wound repair is a complex physiological process that often leads to bacterial infections,which significantly threaten human health.Therefore,developing wound-healing materials that promote healing and prevent bacterial infections is crucial.In this study,the coordination interaction between sulfhydryl groups on dithiothreitol(DTT)and MoS_(2)nanosheets is investigated to synthesize a MoS_(2)-DTT nanozyme with photothermal properties and an improved free-radical scavenging ability.Double-bond-modified hyaluronic acid is used as a monomer and is cross-linked with a PF127-DA agent.PHMoD is prepared in coordination with MoS_(2)-DTT as the functional component.This hydrogel exhibits antioxidant and antibacterial properties,attributed to the catalytic activity of catalase-like enzymes and photothermal effects.Under the near-infrared(NIR),it exhibits potent antibacterial effects against gram-positive(Staphylococcus aureus)and gram-negative bacteria(Escherichia coli),achieving bactericidal rates of 99.76%and 99.42%,respectively.Furthermore,the hydrogel exhibits remarkable reactive oxygen species scavenging and antioxidant capabilities,effectively countering oxidative stress in L929 cells.Remarkably,in an animal model,wounds treated with the PHMoD(2.0)and NIR laser heal the fastest,sealing completely within 10 days.These results indicate the unique biocompatibility and bifunctionality of the PHMoD,which make it a promising material for wound-healing applications.