Conformal Fabrication of an Electrospun Nanofiber Mat on a 3D Ear Cartilage-Shaped Hydrogel Collector Based on Hydrogel-Assisted Electrospinning

A facile one-stone-two-birds strategy for fabricating multifunctional 3D nanofibrous scaffolds

Local bacterial infections lead to delayed wound healing and in extreme cases, such as diabetic foot ulcers, to non-healing due to the impaired cellular function in such wounds. Thus, many scientists have focused on developing advanced therapeutic platforms to treat infections and promote cellular proliferation and angiogenesis. This study presents a facile approach for designing nanofibrous scaffolds in three dimensions (3D) with enhanced antibacterial activity to meet the need of treating chronic diabetic wounds. Being a cationic surfactant as well as an antimicrobial agent, octenidine (OCT) makes a 2D membrane hydrophilic, enabling it to be modified into a 3D scaffold in a "one stone, two birds" manner. Aqueous sodium borohydride (NaBH4) solution plays a dual role in the fabrication process, functioning as both a reducing agent for the in situ synthesis of silver nanoparticles (Ag NPs) anchored on the nanofiber surface and a hydrogen gas producer for expanding the 2D membranes into fully formed 3D nanofiber scaffolds, as demonstrated by morphological analyses. Various techniques were used to characterize the developed scaffold (e.g., SEM, XRD, DSC, FTIR, and surface wettability), demonstrating a multilayered porous structure and superhydrophilic properties besides showing sustained and prolonged release of OCT (61% ± 1.97 in 144 h). Thanks to the synergistic effect of OCT and Ag NPs, the antibacterial performance of the 3D scaffold was significantly higher than that of the 2D membrane. Moreover, cell viability was studied in vitro on mouse fibroblasts L929, and the noncytotoxic character of the 3D scaffold was confirmed. Overall, it is shown that the obtained multifunctional 3D scaffold is an excellent candidate for diabetic wound healing and skin repair.

Highly Efficient, Dual-Functional Self-Assembled Electrospun Nanofiber Filters for Simultaneous PM Removal and On-Site Eye-Readable Formaldehyde Sensing

Air pollution containing particulate matter (PM) and volatile organic compounds has caused magnificent burdens on individual health and global economy. Although advances in highly efficient or multifunctional nanofiber filters have been achieved, many existing filters can only deal with one type of air pollutant, such as capturing PM or absorbing and detecting toxic gas. Here, highly efficient, dual-functional, self-assembled electrospun nanofiber (SAEN) filters were developed for simultaneous PM removal and onsite eye-readable formaldehyde sensing fabricated on a commercial fabric mask. With the use of an electrolyte solution containing a formaldehyde-sensitive colorimetric agent as a collector during electrospinning, the one-step fabrication of the dual-functional SAEN filter on commercial masks, such as a fabric mask and a daily disposable mask, was achieved. The electrolyte solution also allowed the uniform deposition of electrospun nanofibers, thereby achieving the high efficiency of PM filtration with an increased quality factor up to twice that of commercial masks. The SAEN filter enabled onsite and eye-readable formaldehyde gas detection by changing its color from yellow to red under a 5 ppm concentrated formaldehyde gas atmosphere. The repetitive fabrication and detachment of the SAEN filter on a fabric mask minimized the waste of the mask while maintaining high filtration efficiency by replenishing the SAEN filters and reusing the fabric mask. Given the dual functionality of SAEN filters, this process could provide new insights into designing and developing high performance and dual-functional electrospun nanofiber filters for various applications, including individual protection and indoor purification applications.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s42765-023-00279-3.

Recent Advances in Macroporous Hydrogels for Cell Behavior and Tissue Engineering

Hydrogels have been extensively used as scaffolds in tissue engineering for cell adhesion, proliferation, migration, and differentiation because of their high-water content and biocompatibility similarity to the extracellular matrix. However, submicron or nanosized pore networks within hydrogels severely limit cell survival and tissue regeneration. In recent years, the application of macroporous hydrogels in tissue engineering has received considerable attention. The macroporous structure not only facilitates nutrient transportation and metabolite discharge but also provides more space for cell behavior and tissue formation. Several strategies for creating and functionalizing macroporous hydrogels have been reported. This review began with an overview of the advantages and challenges of macroporous hydrogels in the regulation of cellular behavior. In addition, advanced methods for the preparation of macroporous hydrogels to modulate cellular behavior were discussed. Finally, future research in related fields was discussed.

Advanced Hydrogels With Nanoparticle Inclusion for Cartilage Tissue Engineering

Cartilage dysfunctions caused by congenital disease, trauma and osteoarthritis are still a serious threat to joint activity and quality of life, potentially leading to disability. The relatively well-established tissue engineering technology based on hydrogel is a promising strategy for cartilage defect repairing. However, several unmet challenges remain to be resolved before its wide application and clinical translation, such as weak mechanical property and compromised bioactivity. The development of nanomedicine has brought a new dawn to cartilage tissue engineering, and composite hydrogel containing nanoparticles can substantially mimic natural cartilage components with good histocompatibility, demonstrating unique biological effects. In this review, we summarize the different advanced nanoparticle hydrogels currently adopted in cartilage tissue engineering. In addition, we also discuss the various application scenarios including injection and fabrication strategies of nanocomposite hydrogel in the field of cartilage repair. Finally, the future application prospects and challenges of nanocomposite hydrogel are also highlighted.

Electrospun Medical Sutures for Wound Healing: A Review

With the increasing demand for wound healing around the world, the level of medical equipment is also increasing, but sutures are still the preferred medical equipment for medical personnel to solve wound closures. Compared with the traditional sutures, the nanofiber sutures produced by combining the preparation technology of drug-eluting sutures have greatly improved both mechanical properties and biological properties. Electrospinning technology has attracted more attention as one of the most convenient and simple methods for preparing functional nanofibers and the related sutures. This review firstly discusses the structural classification of sutures and the performance analysis affecting the manufacture and use of sutures, followed by the discussion and classification of electrospinning technology, and then summarizes the relevant research on absorbable and non-absorbable sutures. Finally, several common polymers and biologically active substances used in creating sutures are concluded, the related applications of sutures are discussed, and the future prospects of electrospinning sutures are suggested.