Significance: Wound dressings are frequently used for wound covering and healing. Ideal wound dressings should provide a moist environment for wounds and actively promote wound healing and skin recovery. The materials used as ideal wound dressings should possess specific properties, thus accelerating skin tissue regeneration process. Recent Advances: Bacterial cellulose (BC) is a natural polymer synthesized by some bacteria. As a kind of natural biopolymer, BC shows good biological activity, biodegradability, and biological adaptability. It has many unique physical, chemical, and biological properties, such as ultrafine nanofiber network, high crystallinity, high water absorption and retention capacity, and high tensile strength and elastic modulus. These excellent properties of BC have laid the foundation for its application as dressing in wound healing. Critical Issues: To optimize the biocompatibility and antimicrobial activity of BC, different methods including microbial fermentation, physical modification, chemical modification, and compound modification have been adopted to modify BC to ensure a better application in wound healing. BC-based wound dressings have been applied in infected wounds, acute traumatic injuries, burns, and diabetic wounds, showing remarkable therapeutic effects on promoting wound healing. Furthermore, there have been some commercial BC-based dressings and they have been utilized in clinical practice. Future Directions: Because of its excellent physicochemical characteristics and biological properties, BC shows high clinical value to be used as a wound dressing for skin tissue regeneration.

Infected superficial wounds were traditionally controlled by topical antibiotics until the emergence of antibiotic-resistant bacteria. Silver (Ag) is a kernel for alternative antibacterial agents to fight this resistance quandary. The present study demonstrates a method for immobilizing small-sized (~5 nm) silver nanoparticles on silica matrix to form a nanosilver–silica (Ag–SiO₂) composite and shows the prolonged antibacterial effects of the composite in vitro. The composite exhibited a rapid initial Ag release after 24 h and a slower leaching after 48 and 72 h and was effective against both methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli). Ultraviolet (UV)-irradiation was superior to filter-sterilization in retaining the antibacterial effects of the composite, through the higher remaining Ag concentration. A gauze, impregnated with the Ag–SiO₂ composite, showed higher antibacterial effects against MRSA and E. coli than a commercial Ag-containing dressing, indicating a potential for the management and infection control of superficial wounds. Transmission and scanning transmission electron microscope analyses of the composite-treated MRSA revealed an interaction of the released silver ions with the bacterial cytoplasmic constituents, causing ultimately the loss of bacterial membranes. The present results indicate that the Ag–SiO₂ composite, with prolonged antibacterial effects, is a promising candidate for wound dressing applications.

Staphylococcus aureus is a notorious pathogen that colonizes implants (orthopedic and breast implants) and wounds with a vicious resistance to antibiotic therapy. Methicillin-resistant S. aureus (MRSA) is a catastrophe mainly restricted to hospitals and emerged to community reservoirs, acquiring resistance and forming biofilms. Treating biofilms is problematic except via implant removal or wound debridement. Nanoparticles (NPs) and nanofibers could combat superbugs and biofilms and rapidly diagnose MRSA. Nanotheranostics combine diagnostics and therapeutics into a single agent. This comprehensive review is interpretative, utilizing mainly recent literature (since 2016) besides the older remarkable studies sourced via Google Scholar and PubMed. We unravel the molecular S. aureus resistance and complex biofilm. The diagnostic properties and detailed antibacterial and antibiofilm NP mechanisms are elucidated in exciting stories. We highlight the challenges of bacterial infections nanotheranostics. Finally, we discuss the literature and provide “three action appraisals”. (i) The first appraisal consists of preventive actions (two wings), avoiding unnecessary hospital visits, hand hygiene, and legislations against over-the-counter antibiotics as the general preventive wing. Our second recommended preventive wing includes preventing the adverse side effects of the NPs from resistance and toxicity by establishing standard testing procedures. These standard procedures should provide breakpoints of bacteria’s susceptibility to NPs and a thorough toxicological examination of every single batch of synthesized NPs. (ii) The second appraisal includes theranostic actions, using nanotheranostics to diagnose and treat MRSA, such as what we call “multifunctional theranostic nanofibers. (iii) The third action appraisal consists of collaborative actions.

Orthopedic applications commonly require the administration of systemic antibiotics. Gentamicin is one of the most commonly used aminoglycosides in the treatment and prophylaxis of infections associated with orthopedic applications, but gentamicin has a short half-life. However, silica nanoparticles (SiO₂ NPs) can be used as elegant carriers for antibiotics to prolong their release. Our goal is the preparation and characterization of SiO₂-gentamicin nanohybrids for their potential antimicrobial administration in orthopedic applications. In vitro gentamicin release profile from the nanohybrids (gentamicin-conjugated SiO₂ NPs) prepared by the base-catalyzed precipitation exhibited fast release (21.4%) during the first 24 h and further extension with 43.9% release during the five-day experiment. Antimicrobial studies of the SiO₂-gentamicin nanohybrids versus native SiO₂ NPs and free gentamicin were performed against Bacillus subtilis (B. subtilis), Pseudomonas fluorescens (P. fluorescens) and Escherichia coli (E. coli). SiO₂-gentamicin nanohybrids were most effective against B. subtilis. SiO₂ NPs play no antimicrobial role. Parallel antimicrobial studies for the filter-sterilized gentamicin were performed to assess the effect of ultraviolet (UV)-irradiation on gentamicin. In summary, the initial fast gentamicin release fits the need for high concentration of antibiotics after orthopedic surgical interventions. Moreover, the extended release justifies the promising antimicrobial administration of the nanohybrids in bone applications.