Biology subjects

Mody, J.

Publications and source records attributed to Mody, J..

3 recordsLinked to original sources

bioRxiv2026

Residual Hair Biomaterial Particulates Improve Dermal Regeneration and Combined with Electrical Stimulation Accelerates Skin Wound Closure

ObjectiveTo evaluate the effect of residual hair (RH) biomaterial particulates, biphasic electrical stimulation (ES), and their combination (RHES) on the kinetics and quality of skin wound healing. MethodEighteen adult albino mice received bilateral, splinted 10-mm full-thickness dorsal excisional wounds and were randomly assigned to one of three animal groups producing four wound-level treatment conditions: untreated control (-) (n = 12), RH (n = 12), ES (n = 6), and combined RHES (n = 6 wounds). Daily wound images were segmented using an AI-assisted workflow: a U-Net (ResNet34 encoder, ImageNet-pretrained, trained on a parallel single-expert tracing study with held-out validation Dice = 0.906) generated initial boundary predictions, each reviewed and corrected as needed. Wound size measures (perimeter, area, equivalent diameter [D_eq], circularity, aspect ratio) were normalized to the day-0 value of each wound and analyzed by linear mixed-effects regression with mouse identity as a random intercept and mouse body weight as a covariate. On day 7, wounds were excised, fixed, processed for histology, and analyzed by Massons trichrome (collagen content in granulation tissue) and GAP-43 immunohistochemistry (a marker of regenerative cellular activity). ResultsAll three treatments significantly accelerated wound closure compared to (-) (Day x Treatment interaction {chi}2(3) = 36.4, ***p < 0.0001). The closure-rate advantages on the log-D_eq scale were ES - 0.047/day (***p < 0.0001), RHES -0.029/day (***p = 0.0005), and RH -0.022/day (**p = 0.0015). By day 7, mean D_eq had decreased to 0.58 of the day-0 value in ES, 0.69 in RHES, 0.73 in RH, and 0.79 in (-). Tissue analyses revealed treatment-specific differences in healing quality: RH and RHES wounds contained 6.1x and 8.5x more collagen in granulation tissue than (-) (both **p = 0.002 vs (-); both **p = 0.009 vs ES), and showed approximately 16x and 27x greater mean GAP-43 expression than (-), respectively; the RHES increase remained significant after Bonferroni correction (adjusted *p = 0.042), whereas the RH increase did not (adjusted p = 0.058). ES alone did not significantly increase either collagen content or GAP-43 expression. Wound shape was more circular and more stable across days in RH-containing groups. Mouse body weight did not predict closure, whereas image-derived dryness, eschar coverage, and wound contraction were significant negative predictors of measured wound size. ConclusionES, RH, and RHES each significantly improve wound closure kinetics. The improvement appears mechanistically distinct: ES principally accelerates closure rate, while RH principally enhances tissue-level regenerative markers (collagen deposition and GAP-43 expression). RHES combines both advantages. Declaration of interestDr. de Guzman is the inventor on a pending patent covering residual hair biomaterial methods and use and a provisional patent on powderized version, both owned by Hofstra University, and is the founder of a company developing wound care products based on the technology. The study was conducted independently. Data are available upon reasonable request.

bioengineering↗

bioRxiv2026

Biomechanics of chemically treated hair for continuous 1D strands

Human hair is a keratin-based fiber with mechanical properties relevant to load-bearing biomaterials; however, its smooth cuticle limits fiber-fiber cohesion during textile-style processing. This study examines how controlled chemical decuticularization influences surface morphology and tensile behavior of intact human hair assembled into continuous one-dimensional (1D) strands. Hair was treated with oxidative bleach, sodium hydroxide (NaOH), or formic acid (FA), carded, and spun using a standardized protocol. SEM imaging showed treatment-dependent surface disruption, from minimal cuticle modification (bleach) to partial scale lifting (NaOH) and extensive cuticle removal (FA). Tensile testing revealed significant differences in Youngs modulus, ultimate tensile strength (UTS), and elongation at break (EAB) across treatments (ANOVA, p < 0.05). NaOH-treated strands exhibited the highest modulus (207 MPa), UTS (34 MPa), and moderate extensibility (28%), whereas bleach- and FA-treated strands showed reduced stiffness and strength. Compared with reference yarns, NaOH-treated strands approached the stiffness of wool and retained greater extensibility than cotton. These findings support a processing window in which partial decuticularization enhances fiber cohesion while preserving mechanical integrity. The resulting 1D strands provide a potential building block for woven biomesh structures, motivating further evaluation of durability, cyclic behavior, multi-ply configurations, and computational modeling.

bioengineering↗

bioRxiv2024

Increased burden of rare risk variants across gene expression networks predisposes to sporadic Parkinson's disease

Alpha-synuclein (Syn) is an intrinsically disordered protein that accumulates in the brains of patients with Parkinsons disease and forms intraneuronal inclusions called Lewy Bodies. While the mechanism underlying the dysregulation of Syn in Parkinsons disease is unclear, it is thought that prionoid cell-to-cell propagation of Syn has an important role. Through a high throughput screen, we recently identified 38 genes whose knock down modulates Syn propagation. Follow up experiments were undertaken for two of those genes, TAX1BP1 and ADAMTS19, to study the mechanism with which they regulate Syn homeostasis. We used a recently developed M17D neuroblastoma cell line expressing triple mutant (E35K+E46K+E61K) "3K" Syn under doxycycline induction. 3K Syn spontaneously forms inclusions that show ultrastructural similarities to Lewy Bodies. Experiments using that cell line showed that TAX1BP1 and ADAMTS19 regulate how Syn interacts with lipids and phase separates into inclusions, respectively, adding to the growing body of evidence implicating those processes in Parkinsons disease. Through RNA sequencing, we identified several genes that are differentially expressed after knock-down of TAX1BP1 or ADAMTS19. Burden analysis revealed that those differentially expressed genes (DEGs) carry an increased frequency of rare risk variants in Parkinsons disease patients versus healthy controls, an effect that was independently replicated across two separate cohorts (GP2 and AMP-PD). Weighted gene co-expression network analysis (WGCNA) showed that the DEGs cluster within modules in regions of the brain that develop high degrees of Syn pathology (basal ganglia, cortex). We propose a novel model for the genetic architecture of sporadic Parkinsons disease: increased burden of risk variants across genetic networks dysregulates pathways underlying Syn homeostasis, thereby leading to pathology and neurodegeneration.

cell biology↗