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Pathogenic bacterial infection is the most frequent wound complication, which has become a major clinical and healthcare challenge in wound management worldwide, leading to impaired healing processes, the risk of amputation, and even death. Here, collagen-based nanocomposite dressings (APZC) with broad-spectrum antibacterial activity are developed to promote the infected full-thickness wound healing. Short rod-like shaped ZnO NPs are synthesized and then coated with polydopamine (PDA) to obtain PDA coated ZnO NPs (PDA@ZnO NPs). Afterward, PDA@ZnO NPs are conjugated on the backbone of a collagen chain, and the obtained collagen-PDA@ZnO NPs conjugate is crosslinked by dialdehyde sodium alginate to fabricate APZC dressings. PDA@ZnO NPs show well dispersibility and are uniformly incorporated into the collagen matrix. APZC dressings have interconnected microporous structure and great physicochemical properties, besides good blood coagulation performance and well cytocompatibility. APZC dressings demonstrate long-lasting and excellently broad-spectrum antimicrobial activity, which can relieve the inflammatory reaction by killing pathogenic bacteria and induce the generation of blood vessels and the orderly deposition of collagen in the wound site, thus promoting infected full-thickness wound healing without obvious scar formation. Overall, the functionalized collagen-based nanocomposite dressings have great potential in the clinical treatment against bacteria-associated wound infection.

Nanoparticle drug delivery systems have drawn considerable attention worldwide due to their unique characteristics and advantages in anticancer drug delivery. Herein, the curcumin (Cur) loaded nanomicelles with two-stage drug release behavior were developed. β-Cyclodextrin (β-CD) and cholesterol were conjugated onto both ends of the poly(ethylene glycol) (PEG) chain to obtain an amphiphilic β-CD-PEG-Chol. The Cur was loaded into the cavities of β-CD and nanomicelle when the β-CD-PEG-Chol self-assembled to the Cur@β-CD-PEG-Chol nanomicelles (Cur@CPC NMs). These Cur@CPC NMs are spherical particles with a particle size of 120.9 nm. The Cur drug loading capacity of Cur@CPC NMs are 61.6 ± 6.9 mg/g. The release behavior of Cur from Cur@CPC NMs conformed to a two-stage mode of "burst-release followed by sustained-release". The prepared Cur@CPC NMs possess high storage stability and excellent hemocompatibility. Moreover, these Cur@CPC NMs exhibit satisfactory antioxidant activity and anticancer activity, resulting in significant reduction in intracellular H 2 O 2 -induced ROS and a nearly 50% lethality rate of HepG-2 cells. Meanwhile, the Cur@CPC NMs show good anti-inflammatory activity, by which the secretion of inflammatory factors of IL-6 and TNF-α are inhibited. Overall, the developed Cur@CPC NMs show application prospects in anticancer drug delivery systems.

The use of the guided bone regeneration technique in oral surgery has been proven to be an effective method for repairing alveolar bone defects. However, the success of this technique heavily relies on the barrier membrane used. Collagen is the most frequently used raw material to fabricate a resorbable barrier membrane, which has some drawbacks during clinical application, such as poor mechanical properties and rapid biodegradation. To address these issues, a new approach was developed for the preparation of collagen-based heterogeneous bilayer membranes, which involves a combination of physical treatment and biocompatible chemical cross-linking. The dialdehyde carboxymethyl cellulose was used to cross-link collagen to fabricate the membrane, and dehydrothermal (DHT) treatment was applied to enhance its properties. The results showed that DHT treatment apparently improved the structure stability and compression strength in both dry and swollen states. The biodegradation rate of the bilayer membrane was depressed, and the porosity was improved by dehydrogenation. The bilayer membrane was found to have good cytocompatibility. Moreover, the compact lower layer of the bilayer membrane possessed a strong barrier function to fibroblasts while the loose upper layer was able to enhance the adhesion, proliferation, and osteogenic differentiation of osteoblasts. Overall, the collagen-based heterogeneous bilayer membrane has great potential for the application in guided bone regeneration. For the membrane, the improved mechanical properties, reduced biodegradation rate, and enhanced osteoblast response make it a promising material for oral surgery applications.

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