Quaternary Pullulan-Functionalized 2D MoS₂ Glycosheets: A Potent Bactericidal Nanoplatform for Efficient Wound Disinfection and Healing

Abstract

Rapid emergence of multidrug-resistant bacterial strains has posed a global threat to public health. Hospital-acquired infections, especially in diabetic and burn patients, severely impede the process of wound healing, thereby causing high mortality. This calls for developing a new biomaterial that synergistically destroys pathogenic strains and also helps in promoting wound healing without causing any resistance generation. A new and highly potent antibacterial agent has been developed by integrating the bactericidal and wound healing properties of MoS2 nanosheets and a recently developed quaternized polysaccharide, pullulan (CP), into a single nanoplatform for accelerated wound therapy. MoS2 nanosheets are noncovalently functionalized with quaternized pullulan to yield glycosheets (MCP) that efficiently eradicate both Gram-negative Escherichia coli (5 μg/mL) and Gram-positive Staphylococcus aureus (10 μg/mL) within a short period of 4 h, through a synergistic action of membrane damage and chemical oxidation. MoS2 nanosheets coupled with CP exert a membrane-directed bactericidal action through distinct mechanisms of “pore-forming” and “non-pore-forming” pathways, respectively, whereas oxidative stress is induced by MoS2 nanosheets alone to collectively kill the pathogens. The MCP glycosheets have good biocompatibility and are also capable of disrupting and eradicating mature biofilms. Rapid and highly efficient in vivo wound disinfection and healing occurred upon MCP treatment through the reduction of inflammation and promotion of cellular proliferation and tissue remodeling. Thus, MCP glycosheets can emerge as a safe and potential biomaterial for better wound care management.

Biocompatible quaternary pullulan functionalized 2D MoS2 glycosheet-based non-leaching and infection-resistant coatings for indwelling medical implants

“…In our previous study, 25 we reported the highly efficient antibacterial and wound healing efficiency of MCP glycosheets against both Gram-positive and Gram-negative bacteria through a combined action of the individual antibacterial properties of MoS 2 nanosheets and CP polysaccharide. In this study, we further exploited this property of MCP glycosheets to fabricate antibacterial coatings for medical implants.…”

“…To begin with, the fabrication of MCP glycosheet coated substrates, positively charged MCP glycosheets were first synthesized in a one-step process of ultrasonication assisted exfoliation of MoS 2 using cationic polysaccharide, CP, as both exfoliating and functionalizing agent, as reported in our previous study. 25 These cationic MCP glycosheets are decorated with quaternary amine and hydroxyl groups on its surface, which help in their attachment to the surface of SS and PVF substrates using polydopamine as an anchorage layer. The SS and PVF substrates were dipped in dopamine solution for a specific time to deposit a thin layer of polydopamine (PDA) on the surface of these substrates.…”

“…Quaternized pullulan functionalized MoS 2 glycosheets were synthesized according to the protocol reported in our previous study. 25 In brief, bulk MoS 2 was dispersed in an aqueous solution of quaternized pullulan (CP) and then subjected to ultrasonication-mediated and cationic polysaccharide-assisted exfoliation and simultaneous functionalization. The dispersion was probe sonicated for 4 h, followed by centrifugation to remove the unexfoliated bulk from the exfoliated MoS 2 nanosheets.…”

Cationic dextrin nanoparticles for effective intracellular delivery of cytochrome C in cancer therapy

“…Dextrin was initially cationized by incorporating quaternary ammonium groups onto the polymeric backbone using GTMAC following a process reported earlier. 31,35,36 Cyt C was suspended in an alkaline buffer of pH 11, higher than its pI (10.8), which made the suspended protein negatively charged. The protein suspension (500 μg) was allowed to stir along with the polymer cationic dextrin (CD) at a concentration of 0.5 mg mL −1 for 30 min to interact electrostatically with each other.…”

Unveiling the antibacterial strategies and mechanisms of MoS2: a comprehensive analysis and future directions

“…For 2D MoS 2 sheets, they have a large surface area and can be easily functionalized. 63 This makes them effective in inhibiting bacterial growth. They are also versatile and can be incorporated into various materials.…”