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Houshyar, S.

Publications and source records attributed to Houshyar, S..

2 recordsLinked to original sources
bioRxiv2026

Injectable Electrospun Hydrogel with Antimicrobial, pH Sensing Nanoparticles for Local Infection Control and Monitoring

Most antimicrobial drug candidates currently in development are derivatives of established antibiotic classes. In contrast, antimicrobial heteroatom-doped carbon quantum dot (COD) nanoparticles vastly differ from their chemical antibiotic counterparts and exhibit potent antibacterial activity and favourable biocompatibility, representing a promising alternative strategy, particularly for topical applications. Here, we report the incorporation of cobalt-doped carbon quantum dots (Co-CODs) into injectable, biocompatible hydrogels capable of both sensing pH and eliminating bacteria. Ultrasmall Co-CODs demonstrated broad-spectrum activity against gram-positive Methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative Pseudomonas aeruginosa (PAO1), mediated by membrane hyperpolarisation and reactive oxygen species (ROS) induced membrane damage. The particles showed negligible effect on primary fibroblast and endothelial cell viability at concentrations that were bactericidal to MRSA. Polymeric hydrogels were fabricated via electrospinning of chitosan, polyvinylpyrrolidone (PVP), and polyvinyl alcohol (PVA) polymer blends incorporating Co-COD and pH-responsive HPTS particles. This approach provided accurate measurement of environmental pH within the physiological range observed across healthy and chronic wounds. In vivo, the injectable hydrogels exhibited robust antimicrobial efficacy against MRSA without impairing wound closure relative to untreated controls, while also reducing inflammatory immune responses in infected tissues. Collectively, these findings demonstrate the potential of ultrasmall metal-doped CODs for infection control and their integration into 3D matrices as multifunctional theragnostic platforms. ToC (<60 words describe the main results)Ultrasmall antimicrobial carbon nanoparticles were incorporated into polymeric hydrogels containing a pH-responsive probe. This platform enabled detection across a physiologically relevant pH range of 5.0-6.5, spanning conditions associated with both healthy healing and chronically infected wounds. The hydrogel demonstrated strong antibacterial activity by generating damaging reactive oxygen species, and, in mice, effectively controlled infection while reducing pro-inflammatory immune responses. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=171 SRC="FIGDIR/small/736887v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@1a52b32org.highwire.dtl.DTLVardef@b6eed2org.highwire.dtl.DTLVardef@1f94143org.highwire.dtl.DTLVardef@12b9ff3_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOScheme 1:C_FLOATNO Antimicrobial nanoparticle-doped hydrogel glows in alkaline wound conditions which are representative of chronic infections. Once in the wound bed, the hydrogel removes all MRSA infection, reducing inflammatory macrophage (iNOS) and neutrophil (MPO) populations, and restores healthy wound collagen deposition. C_FIG

bioengineering↗
bioRxiv2025

Bioengineered visible polymeric mesh to enhance urogynaecological health

Pelvic floor disorders, including pelvic organ prolapse and stress urinary incontinence, are prevalent health concerns, affecting approximately 50% of females over their lifetime, with about 75% of women over 65 years of age being impacted. Traditional surgical interventions, such as transvaginal mesh implants, have led to numerous complications, resulting in their prohibition in several countries. This study introduces an innovative composite mesh designed to mitigate these issues by combining polymethylmethacrylate and thermoplastic polyurethane, further enhanced with iodine-doped carbon nanoparticles to enable visibility via medical imaging. The mesh is coated with 2-methacryloyloxyethyl phosphorylcholine polymer to prevent protein adsorption and promote tissue regeneration. In vitro studies showed high cell viability and low protein adsorption, indicating excellent biocompatibility. Implantation of mesh (with or without iodine) in mice revealed no adverse effects on overall animal health. Mouse spleen weight (an indicator of inflammation) was similar between groups; however, levels of some cytokines (i.e., IL-10, IL-17A and GM-CSF) were elevated following implantation of iodinated mesh in mice suggesting that further refinement of the composite mesh is required. Analysis of the fecal microbiome, which is correlated with physiological states, showed that sham and iodinated mesh implant groups maintained consistent microbial profiles with stable diversity (richness and evenness) measures over time. In contrast, the non-iodinated mesh group exhibited decreased species richness post mesh implantation, likely due to a distinct starting microbiome composition prior to implantation. This research is envisaged to contribute to a safer and more effective solution for treating pelvic floor disorders, providing non-invasive post-implantation monitoring and enhanced mechanical compatibility of surgical mesh with native tissue. Our findings demonstrate that this composite mesh possesses mechanical properties that closely mimic human tissue, ensuring biocompatibility, strength, and flexibility without stimulating significant inflammatory or foreign body responses.

bioengineering↗