Urinary bladder matrix (UBM) is one of the most studied extracellular matrixes (ECM) in the tissue engineering field. Although almost all of the UBM hydrogels were prepared by using peracetic acid (PAA), recent studies indicated that PAA was not a trustworthy way to decellularize UBM. A stronger detergent, such as sodium dodecyl sulfate (SDS), may help tackle this issue; however, its effects on the hydrogels’ characteristics remain unknown. Therefore, the objective of this study was to develop a more reliable protocol to decellularize UBM, using SDS, and to compare the characteristics of hydrogels obtained from this method to the widely employed technique, using PAA. The results indicated that SDS was superior to PAA in decellularization efficacy. Different decellularization methods led to dissimilar gelation kinetics; however, the methods did not affect other hydrogel characteristics in terms of biochemical composition, surface morphology and rheological properties. The SDS-treated hydrogels possessed excellent cytocompatibility in vitro. These results showed that the SDS decellularization method could offer a more stable and safer way to obtain acellular UBM, due to reducing immunogenicity. The hydrogels prepared from this technique had comparable characteristics as those from PAA and could be a potential candidate as a scaffold for tissue remodeling.

Mesenchymal stem cells (MSCs) possess immunomodulatory properties and capacity for endogenous regeneration. Therefore, MSC therapy is a promising treatment strategy for COVID-19. However, the cells cannot stay in the lung long enough to exert their function. The extracellular matrix from porcine bladders (B-ECM) has been shown not only to regulate cellular activities but also to possess immunoregulatory characteristics. Therefore, it can be hypothesized that B-ECM hydrogel could be an excellent scaffold for MSCs to grow and could anchor MSCs long enough in the lung so that they can exhibit their immunomodulatory functions. In this study, ECM degradation products and a co-culture system of MSCs and macrophages were developed to study the immunomodulatory properties of ECM and MSCs under septic conditions. The results showed that B-ECM degradation products could decrease pro-inflammatory and increase anti-inflammatory cytokines from macrophages. In an in vivo mimicking co-culture system, MSCs cultured on B-ECM hydrogel exhibited immunomodulatory properties at both gene and protein levels. Both B-ECM degradation products and MSC conditioned medium supported the wound healing of alveolar epithelial cells. The results from the study could offer a basis for investigation of immunomodulation by ECM and MSCs before conducting in vivo experiments, which could later be applied in regenerative medicine.

Porcine urinary bladder is one of the most used organs to fabricate extracellular matrix (ECM) hydrogel. Although there are two different ECM types inside a bladder, i.e., urinary bladder matrix (UBM) and a subtype ECM (sECM), most studies have only employed UBM for hydrogel fabrication, and overlooked the potential use of sECM. In another aspect, the delamination of UBM from bladders is a time-consuming process; consequently, the use of the whole bladder (WB) will likely increase production yield. Therefore, the objective of this study was to fabricate hydrogels from sECM and WB and compare them to UBM. The results indicated that different layers of the bladder shared almost the same biochemical composition. In terms of gelation kinetics, rheology and morphology, although hydrogels from UBM and sECM exhibited some discrepancies, those from UBM and WB interestingly possessed almost the same characteristics. In in vitro studies, all the hydrogels possessed nearly the same biochemical effects towards L929 viability and C2C12 differentiation. These results could preliminarily indicate that the use of sECM should no longer be ignored, and WB could be a promising substitution for UBM hydrogels, eliminating the need for time-consuming delamination processes, as well as increasing the possibility of mass production.

Recent studies have highlighted the potential of urinary bladder matrix (UBM) derived from decellularized porcine urinary bladder as a bioactive hydrogel. Despite its complex composition of over 100 proteins, Type I collagen is the primary constituent of UBM. Caco-2 cells are widely used as an in vitro model of the intestinal epithelium; however, to date, no published study has evaluated the effects of UBM on Caco-2 cells. In this study, Electric Cell–Substrate Impedance Sensing (ECIS) was used to measure Caco-2 cell attachment and wound-healing migration on UBM-coated microelectrodes. Our results demonstrate that UBM hydrogel coating at 0.2 mg/mL significantly accelerates cell attachment and enhances migration rates compared to uncoated controls. These stimulatory effects were comparable to those observed with 0.2 mg/mL Type I collagen, suggesting that UBM can function as effectively as Type I collagen. We further monitored barrier formation in Caco-2 cells cultured on UBM-coated transwell membrane inserts using TEER measurements and scanning electron microscopy. The TEER values reached 300 Ω·cm² within three days, indicating the rapid establishment of mature tight junctions. Overall, these results show that UBM hydrogel coatings are effective substrates for Caco-2 cells, performing as well as Type I collagen in all our tests.

Wound infection, inadequate local hemostasis, and delayed healing remain major complications following surgery and in chronic wounds, contributing to substantial morbidity and healthcare costs. Effective wound management requires materials that simultaneously prevent infection, support hemostasis, promote tissue repair, and maintain biocompatibility. Here, we synthesized Z-pQAM, a zwitterionic-quaternary ammonium microparticle combining bactericidal and hemostatic functionalities, and evaluated its biocompatibility, antimicrobial efficacy, hemostatic performance, and wound healing effects. Fourier-transform infrared spectroscopy confirmed stepwise synthesis and quaternization. Z-pQAM exhibited >7-log10 reduction against Escherichia coli and Staphylococcus aureus and >5-log10 reduction against methicillin-resistant S. aureus at 200 mg/mL, while maintaining 50% at day 3, and enhanced collagen deposition and organization by day 12. Collectively, these findings support Z-pQAM as a cytocompatible and hemocompatible microparticle with integrated antimicrobial and hemostatic activity that improves wound healing, highlighting its potential as a multifunction topical wound dressing for clinical wound management.