Huazhen Liu

Electrospinning is a powerful biofabrication technique for constructing fibrous scaffolds that mimic extracellular matrix architectures. However, the process is highly nonlinear and involves strongly coupled parameters, making fiber architecture and biological performance difficult to control empirically and limits reproducibility. Most machine learning (ML) studies still focus on static correlations between processing parameters and outcomes rather than on dynamic modeling of electrospinning evolution and regulation, thereby hindering real-time, precise process control. Here, we establish a data-driven framework that links process parameters, Taylor cone geometry, and nanofiber/cell outcomes through high-speed imaging and ML. A custom image-processing pipeline is developed to automatically extract cone angle, height, and width from in situ images with improved accuracy via a rotating-ray–based geometric algorithm. Using datasets collected from three representative polymer systems (PVDF, PVB, and PEO), random forest models outperform support vector machine and minimum description length, achieving moderate-to-good prediction of Taylor cone descriptors (R²≈0.57-0.83) across varied voltages, flow rate, and needle–collector distances. We further extend this framework to PEO-based cell electrospinning. By correlating predicted cone geometries with experimentally measured viability of 293T cells and umbilical cord mesenchymal stem cells, we identify a Taylor cone “safe window” that simultaneously stabilizes jet formation and preserves cell survival (>95%). Guided by this window, a bilayer cell-laden scaffold comprising a PVB support layer and a PEO–cell layer is fabricated with improved process robustness. This enables stable delivery of high-density, highly viable cells and facilitates the fabrication of three-dimensional cell-laden nanofiber scaffolds. Overall, this Taylor cone analysis, ML-guided strategy provides a quantitative framework for process-window identification in polymer and cell electrospinning, and may support future integration with real-time monitoring, online inference, and closed-loop control in intelligent biofabrication.

For healing full-thickness skin defects caused by severe injury, skin substitute grafts with structural and compositional biomimicry are critical. Vascularized spheroids, as highly active biological building blocks, can be applied in biomanufacturing to fabricate functional repair constructs. However, current methods of biofabricating endothelialized spheroids still face multiple technical limitations, including low throughput, poor uniformity, and insufficient controllability and observability. Furthermore, there is inadequate control over the spatial arrangement of the spheroids during vascularized construct biomanufacturing. We proposed a synergistic, shape-controlled spheroid–hydrogel biomanufacturing method to address these issues, and developed a highly integrated, one-stop bioprinting platform for spheroids (OBPS) with real-time monitoring. We focused on key biomanufacturing stages, spheroid fabrication, bioprinting, and in vivo validation, to establish an integrated technical framework providing for ‘fabrication–culture–assembly–application.’ Using the OBPS, we fabricated endothelialized spheroids by co-culturing human fibroblasts and human umbilical vein endothelial cells, printed fibrinogen-supplemented gelatin methacryloyl hydrogel, and bioprinted spheroids and hydrogels in situ onto full-thickness skin defects in nude mice. Animal experiments show that shape-controlled endothelialized spheroids significantly accelerated wound closure, suppressed inflammation, promoted neovascularization and collagen remodeling, and exhibited excellent tissue integration and repair potential. The OBPS system provides a novel and effective treatment for wound healing.

Timely management of skin defects requires simultaneous filling of deep tissue defects with a scaffold and coverage of the surface to support tissue repair and barrier protection. However, conventional dressings and dermal substitutes often rely on in vitro prefabrication and secondary application, which are time-consuming and results in suboptimal interfacial integration. In situ printing enables point-of-care fabrication of dressings for early wound care; however, existing hand-held in situ printers typically employ a single fabrication modality, making it difficult to rapidly construct micro-nano composite dressings with combined scaffold-barrier functions at the bedside. To address these limitations, we developed a hand-held, digital, multiprocess in situ printing system for point-of-care fabrication of micro-nano composite dressings. The system integrates in situ photo-cross-linking extrusion printing, air-assisted spraying, and electrospinning, and incorporates an adaptive temperature-control module to stabilize the gelation of thermoresponsive hydrogels. In addition, wireless smartphone connectivity enables mobile configuration of key process parameters and precise material dispensing, thereby ensuring stable mode switching and continuous fabrication. The results show that the extrusion module enables stable printing of multiple hydrogels and supports in situ photo-cross-linking of cell-laden constructs with cell viability above 90%, indicating a cell-friendly fabrication process. The spraying mode allows rapid deposition of hydrogel precursors and achieves sustained drug release. The electrospinning mode enables the fabrication of nanofibrous membranes from different materials. Among them, cell-laden electrospinning with PEO achieved a cell viability of over 92%, while the PVB fibrous layer fabricated in this mode exhibited a porosity of 73.2%, providing both protection and gas exchange capability. Through multiprocess integration, a nanofibrous barrier layer can be rapidly constructed on the hydrogel surface, yielding a micro-nano composite dressing featuring a microscale hydrogel scaffold and a nanoscale fibrous barrier within a short time. The platform enables integrated fabrication of micro-nano composite dressings in rat and porcine wound models. This "arrive-on-site to scaffold-barrier dressing formation" capability demonstrates the technical feasibility of using a hand-held multiprocess printer for rapid, parametrically controlled wound coverage and provides a device platform for future studies on emergency wound management and personalized dressing fabrication.

Targeting overactivated myofibroblasts is a potential treatment for hypertrophic scarring. Evodiamine, an indole alkaloid derived from Evodiae fructus, has attracted increasing attention for its antitumor efficacy to inhibit proliferation and promote apoptosis of tumor cells. However, its role on hypertrophic scarring remains unexplored. Hence, we engineered a boronic acid-functionalized evodiamine derivative (BED) triggered by pathology-specific reactive oxygen species (ROS) to target myofibroblasts to ameliorate hypertrophic scarring with minimal toxicity to normal fibroblasts. In vitro experiments presented that BED could be triggered by the increased ROS in myofibroblasts and thus selectively induce apoptosis and suppress proliferation of myofibroblasts, inhibit myofibroblast contraction and migration, and suppress α-SMA and collagen expression. The underlying antiscar mechanism was partly mediated by disrupting microtubules and microfilaments, thereby suppressing the proliferation and contraction of myofibroblasts. To optimize delivery and therapeutic efficacy, the exosome-encapsulated delivery system was further developed, and the results showed that exosomes-coated BED, enhancing BED cellular internalization while protecting BED from extracellular ROS degradation, achieved the optimized therapeutic efficacy of hypertrophic scarring in vivo by targeting myofibroblasts. This approach represents a promising therapeutic strategy for hypertrophic scarring and other fibrotic pathologies.

Hypertrophic scarring from burns can lead to sleep disturbances in children and significantly impact their quality of life and that of their caregivers. This study investigated the sleep quality of 9 pediatric patients with hypertrophic scars who underwent ablative fractional carbon dioxide laser (CO2-AFL) surgery. Electrocardiography was recorded before the first CO2-AFL treatment and after the final treatment. Cardiopulmonary coupling software was used to automatically generate sleep reports, including total time in bed, total sleep time, sleep efficiency, sleep latency time, deep sleep time, light sleep time, rapid eye movement sleep time, wake time, and apnea–hypopnea index. This study found that pediatric patients with hypertrophic scars commonly experience sleep disorders, and CO2-AFL surgery could improve sleep quality, including sleep efficiency, deep sleep duration, awakening time, and apnea–hypopnea index. This study provides preliminary objective evidence that CO₂-AFL treatment is associated with improvements in sleep quality parameters in pediatric patients with hypertrophic scars.

Severe skin damage poses a significant clinical challenge, as limited availability of skin donors, postoperative skin defects, and scarring often impair skin function. Traditional two-dimensional (2D) nanofibers exhibit small pore sizes that hinder cellular infiltration, unable to simulate the three-dimensional (3D) structure of the skin. To address these issues, we developed 3D porous nanofiber scaffolds composed of polycaprolactone–polylactic acid–mussel adhesive protein (PLGA-PCL-MAP) using low-temperature electrospinning combined with nano-spray technology. Meanwhile, this 3D scaffold features high porosity, enhanced water absorption, and improved air permeability. The incorporation of mussel adhesive protein (MAP) further increased the scaffold’s adhesive properties and biocompatibility. In vitro experiments demonstrated that the 3D nanofiber scaffolds significantly promoted the adhesion, proliferation, and migration of epidermal keratinocytes (HaCaTs) and human fibroblasts (HFBs), while providing ample space for inward cellular growth. Successful co-culture of HaCaT and HFBs within the scaffold revealed key functional outcomes: HaCaTs expressed keratinocyte differentiation markers CK10 and CK14, while HFBs actively secreted extracellular matrix components critical for wound healing, including collagen I, collagen III, and fibronectin. This skin substitute with a composite structure of epidermis and dermis based on three-dimensional nanofiber scaffolds can be used as an ideal skin replacement and is expected to be applied in wound repair in the future.

Spheroids, as three-dimensional (3D) cell aggregates, can be prepared using various methods, including hanging drops, microwells, microfluidics, magnetic manipulation, and bioreactors. However, current spheroid manufacturing techniques face challenges such as complex workflows, the need for specialized personnel, and poor batch reproducibility. In this study, we designed a support-free, 3D-printed microwell chip and developed a compatible low-cell-adhesion process. Through simulation and experimental validation, we rapidly optimized microwell size and the coating process. We successfully formed three types of spheroids—human immortalized epidermal cells (HaCaTs), umbilical cord mesenchymal stem cells (UC-MSCs), and human osteosarcoma cells (MG63s)—on the chip. Fluorescent viability staining confirmed the biocompatibility and reliability of the chip. Finally, drug response experiments were conducted using the chip. Compared to traditional methods, our proposed strategy enables high-throughput production of size-controlled spheroids with excellent shape retention, while enhanced gas exchange during culture improves differentiation marker expression. This platform provides an efficient and cost-effective solution for biosensing applications, such as drug screening, disease modeling, and personalized therapy monitoring. Furthermore, the chip shows significant potential for real-time in vitro monitoring of cellular viability, reaction kinetics, and drug sensitivity, offering valuable advancements in biosensor technology for life sciences and medical applications.

Mussel refers to a marine organism with strong adhesive properties, and it secretes mussel adhesion protein (MAP). The most vital feature of MAP is the abundance of the 3,4-dihydroxyphenylalanine (DOPA) group and lysine, which have antimicrobial, anti-inflammatory, antioxidant, and cell adhesion-promoting properties and can accelerate wound healing. Polydopamine (PDA) is currently the most widely used mussel-inspired material characterized by good adhesion, biocompatibility, and biodegradability. It can mediate various interactions to form functional coatings on cell-material surfaces. Nanofibers based on MAP and mussel-inspired materials have been exerting a vital role in wound repair, while there is no comprehensive review presenting them. This Review introduces the structure of MAPs and their adhesion mechanisms and mussel-inspired materials. Second, it introduces the functionalized modification of MAPs and their inspired materials in electrospun nanofibers and application in wound repair. Finally, the future development direction and coping strategies of MAP and mussel-inspired materials are discussed. Moreover, this Review can offer novel strategies for the application of nanofibers in wound repair and bring about new breakthroughs and innovations in tissue engineering and regenerative medicine.