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Highlights: Derived from silica photonic crystals, inverse opal microspheres have a regularly connected porous structure and inherit structural color properties. Combined with the stable scaffold and the photothermal phase-transition of the secondary filling material, the inverse opal composite microspheres are endowed with self-healing properties and the ability for controllable drug release. Inverse opal microspheres were significantly treated for diabetic wound, via promoting tissue regeneration, collagen deposition and angiogenesis. Meanwhile, the release of drugs could be monitored by the structural color characteristic. Chronic diabetic wounds confront a significant medical challenge because of increasing prevalence and difficult-healing circumstances. It is vital to develop multifunctional hydrogel dressings, with well-designed morphology and structure to enhance flexibility and effectiveness in wound management. To achieve these, we propose a self-healing hydrogel dressing based on structural color microspheres for wound management. The microsphere comprised a photothermal-responsive inverse opal framework, which was constructed by hyaluronic acid methacryloyl, silk fibroin methacryloyl and black phosphorus quantum dots (BPQDs), and was further re-filled with a dynamic hydrogel. The dynamic hydrogel filler was formed by Knoevenagel condensation reaction between cyanoacetate and benzaldehyde-functionalized dextran (DEX-CA and DEX-BA). Notably, the composite microspheres can be applied arbitrarily, and they can adhere together upon near-infrared irradiation by leveraging the BPQDs-mediated photothermal effect and the thermoreversible stiffness change of dynamic hydrogel. Additionally, eumenitin and vascular endothelial growth factor were co-loaded in the microspheres and their release behavior can be regulated by the same mechanism. Moreover, effective monitoring of the drug release process can be achieved through visual color variations. The microsphere system has demonstrated desired capabilities of controllable drug release and efficient wound management. These characteristics suggest broad prospects for the proposed composite microspheres in clinical applications. [ABSTRACT FROM AUTHOR]

Localized chemotherapy is emerging as a potential strategy for cancer treatment due to its low systemic toxicity. However, the immune evasion of tumor cells and the lack of an intelligent design of the delivery system limit its clinical application. Herein, photothermal responsive microcarriers are designed by microfluidic electrospray for colorectal tumor treatment. The microcarriers loaded with Cangrelor, 5‐FU and MXene (G‐M@F/C+NIR) show sustained delivery of antiplatelet drug Cangrelor, thus inhibiting the activity of platelets, interactions of platelet‐tumor cell, as well as the tumor cells invasion and epithelial‐mesenchymal transition (EMT). In addition, the sustained delivery of chemotherapeutics 5‐FU and the photothermal effect provided by MXene enable the microcarriers to inhibit tumor cells proliferation and migration. In vivo studies validate that the G‐M@F/C+NIR microcarriers significantly inhibites tumor growth, decreased the expression of Ki‐67 in tumor cells and vascular endothelial growth factor (VEGF) in the tumor microenvironment, while increased the expression of E‐cadherin. It is believe that by means of the proposed photothermal responsive microcarriers, the synergistic strategy of platelet inhibition, chemotherapy, and photothermal therapy can find practical applications in cancer treatment. [ABSTRACT FROM AUTHOR]

Many hydrogel patches are developed to solve the pervasive and severe challenge of complex wound healing, while most of them still lack satisfactory controllability and comprehensive functionality. Herein, inspired by multiple creatures, including octopuses and snails, a novel muti‐functional hydrogel patch is presented with controlled adhesion, antibacterial, drug release features, and multiple monitoring functions for intelligent wound healing management. The patch with micro suction‐cup actuator array and a tensile backing layer is composed of tannin grafted gelatin, Ag‐tannin nanoparticles, polyacrylamide (PAAm) and poly(N‐isopropylacrylamide) (PNIPAm). In virtue of the photothermal gel‐sol transition of tannin grafted gelatin and Ag‐tannin nanoparticles, the patches exert a dual anti‐microbial effect and temperature‐sensitive snail mucus‐like features. In addition, as the "suction‐cups" consisting of thermal responsive PNIPAm can undergo a contract‐relax transformation, the medical patches can adhere to the objects reversibly and responsively, and release their loaded vascular endothelial growth factor (VEGF) controllably for wound healing. More attractively, benefiting from their fatigue resistance, self‐healing ability of the tensile double network hydrogel, and electrical conductivity of Ag‐tannin nanoparticles, the proposed patches can report multiple wound physiology parameters sensitively and continuously. Thus, it is believed that this multi‐bioinspired patch has immense potential for future wound healing management. [ABSTRACT FROM AUTHOR]

Biological scaffolds hold promising perspectives for random skin flap regeneration, while the practical application is greatly limited by their insufficient vascularization ability and the lack of responsiveness during the dynamical healing process. Herein, a novel MXene‐incorporated hollow fibrous (MX‐HF) scaffold with dynamically responsive channels is presented for promoting vascularization and skin flap regeneration by using a microfluidic‐assisted 3D printing strategy. Benefiting from the photothermal conversion capacity of the MXene nanosheets and temperature‐responsive ability of poly(NIPAM) hydrogels in the MX‐HF scaffolds, they display a near‐infrared (NIR)‐responsive shrinkage/swelling behavior, which facilitates the cell penetration into the scaffold channels from the surrounding environment. Moreover, by incorporating vascular endothelial growth factor (VEGF) into the hydrogel matrix for controllable delivery, the MX‐HF scaffolds can achieve promoted proliferation, migration, and proangiogenic effects of endothelial cells under NIR irradiation. It is further demonstrated in vivo that the NIR‐responsive VEGF@MX‐HF scaffolds can effectively improve skin flap survival by promoting angiogenesis, decreasing inflammation, and attenuating apoptosis in skin flaps. Thus, it is believed that such responsive MX‐HF scaffolds are promising candidates for clinical random skin flap regeneration as well as other diverse tissue engineering applications. [ABSTRACT FROM AUTHOR]

Medical patches play an important role in wound healing because of their tissue conformality, drug release capacity, and convenient operation. Great efforts have been devoted to developing new‐generation patches with distinctive features promoting wound healing. Here, inspired by the structure of octopus suction cups and the component of natural tissue, a biocompatible wound patch with selective adhesiveness and individualized design using a combined strategy of template‐replication and mask‐guided lithography is presented. Such patches are based on Ecoflex film with suction‐cup‐mimicking microstructures to adhere to normal skin and with biocompatible gelatin methacryloyl (GelMA) hydrogel to contact wounded areas. An ultraviolet mask with a tailorable pattern is employed to shape the GelMA hydrogel into customized geometry replicating individual wound areas, and thus both adhesion and antiadhesion properties are integrated into the same patch. In addition, vascular endothelial growth factor is loaded to accelerate the healing process. Based on these advantages, the authors demonstrate that the present patches not only adhere to different skin surfaces, but also promote the treatment of a rat cutaneous wound model. Thus, it is believed that this versatile patch can break through the limitation of traditional patches and be ideal candidates for wound healing and related biomedical applications. [ABSTRACT FROM AUTHOR]

• Gallium-based liquid metals are used for photothermal antibacterial and drug release. • The ultrasound reduces the surface tension of the gallium-based liquid metal for uniform doping in the hydrogel presolution. • The 3D printing gives the hydrogel scaffolds an adjustable shape and size. • Gelatin/gellan gum are used as extruded 3D printed ink with good hydrodynamic performance. Hydrogels patches hold significant promise for wound healing. Endeavors have been dedicated to the improvement of hydrogel patch functionalities, with the aim of achieving systematic wound management. Herein, we present liquid metal (LM) hybrid antibacterial hydrogel scaffolds for wound healing via the 3D printing strategy. Gelatin/gellan gum-based hydrogel ink is adopted for printing the scaffolds, with LM microdroplets integrated within. Due to the excellent photothermal responsiveness of LM microdroplets, the LM hybrid scaffolds can convert the received near infrared light energy into heat energy, demonstrating controllable antibacterial ability. In addition, vascular endothelial growth factor is introduced into the scaffolds, which can be sustainably released and play an angiogenesis role. In vivo animal experiments demonstrate that this hydrogel scaffolds can effectively assit wound closure by eradicating bacterial infection and promoting angiogenesis. Thus, we believe that the proposed LM hybrid hydrogel scaffolds show promising prospects in wound treatment. [ABSTRACT FROM AUTHOR]

• The Janus microcarriers with sequential release were developed for bone repair. • The Janus microcarriers contain two distinct hemispheres for drug release. • The Janus microcarriers can promote bone repair by angiogenesis and osteogenesis. Growth factor therapy is an effective treatment strategy for bone repair. Research in this field aims to develop functional biomaterials for delivering multiple growth factors in a temporally controllable way and thus improving the therapeutic effect. Herein, inspired by natural bone healing mechanisms that involves early-stage angiogenesis and later-stage osteogenesis, we develop a novel type of Janus microcarriers with sequential actives release ability from microfluidic electrospray for bone regeneration. The Janus microcarriers contain two distinct hemispheres consisting of hyaluronic acid methacryloyl (HAMA) and gelatin methacryloyl (GelMA) hydrogel, respectively. Vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP2) are compartmentalized in different hemispheres of the microcarriers and released sequentially, in a way mimicking the natural bone repair process. In addition, magnetic Fe 3 O 4 @SiO 2 nanoparticles are doped in the microcarriers to facilitate magnetic enrichment and localization of the microcarriers in the bone defect site. Moreover, the GelMA hemisphere facilitates cell migration to the defect site, and the HAMA hemisphere reduces the risk of tissue adhesion. In vivo experiments demonstrate that the Janus microcarriers can effectively promote bone regeneration by coordinating angiogenesis and osteogenesis. We believe this work provides a new approach for the development of novel smart drug vehicles and treatment of bone defects. [ABSTRACT FROM AUTHOR]

• Developing a marine polymer composite microcapsule through microfluidic electrospray technique. • Polymer materials derived from marine organisms have good biocompatibility. • Biomass antibacterial chitosan imparting the microcapsules with antibacterial capacity. • Effective encapsulation of drug promoting its delivery and angiogenesis. • Marine polymer composite microcapsules promoting wound healing. Skin damage is a serious problem that has attracted remarkable attention. Novel wound dressings with optimized compositional and structural design that could adapt to the wound area are highly expected. In this study, we prepare marine polymer composite microcapsules via microfluidic electrospray for promoting wound healing. An alginate (ALG) core and a chitosan (CS) shell formed microcapsules through polyelectrolyte complexation and glutaraldehyde cross-linking. Such composition ensures the great biocompatibility and antibacterial capacity of the microcapsules. Besides, vascular endothelial growth factor (VEGF) can be loaded into the microcapsules as well as released in a sustainable way. Based on these advantages, the microcapsules are casted on the wound site and their roles in inhibiting bacterial growth and promoting angiogenesis during wound closure are demonstrated. These results confirm the values of the microcapsules in wound healing, and we believe that would find potential clinical applications. [ABSTRACT FROM AUTHOR]