Abstract

Disruptions in wound healing can result in pathological outcomes ranging from chronic nonhealing wounds to excessive fibrotic scarring. Hypertrophic scars and keloids are hallmarks of this dysregulation, characterized by abnormal collagen deposition, persistent myofibroblast activation, and disorganized extracellular matrix (ECM) remodeling. Chronic inflammation and oxidative stress play central roles by increasing reactive oxygen species (ROS), which damage essential macromolecules and sustain pro-inflammatory signaling, while promoting the transdifferentiation of fibroblasts into myofibroblasts and the excessive production of ECM proteins, such as collagen and α-smooth muscle actin (α-SMA). This fibrotic cascade leads to tissue stiffness, contractility, and disfigurement, affecting the well-being of over 100 million individuals annually in the developed world. To address these clinical challenges, this study developed a novel, cell-free therapeutic formulation composed of Aloe vera gel-derived extracellular vesicles (Av-EVs) and hyaluronic acid (HA). It also evaluated how the gel extraction method (manual, NB vs. shear-force-based, B) and Aloe vera maturity (young vs. mature) influence the bioactivity of Av-EVs alone and in combination with medium- and high-molecular-weight HA. Experimental readouts were assessed employing radical scavenging assays as well as inflammatory and fibrotic in vitro models. Av-EVs from both extraction methods were successfully isolated, exhibiting spherical morphology and a size range of 150–250 nm. However, notable differences in particle concentration and protein content between NB and B samples highlighted the influence of the extraction technique on vesicle integrity and functionality. Antioxidant assays revealed that NB Av-EVs showed enhanced ROS scavenging capacity, indicating better preservation of redox-active components. Similarly, NB Av-EVs significantly downregulated collagen and α-SMA expression at both gene and protein levels, suggesting strong inhibition of myofibroblast differentiation. Both NB and B Av-EVs rapidly suppressed M1-associated cytokines within 24 hours and promoted M2 polarization over seven days. Crucially, manually extracted Av-EVs derived from mature leaves demonstrated superior anti-inflammatory and antifibrotic efficacy compared to those from younger plants, underscoring the importance of plant maturity in optimizing therapeutic outcomes. Furthermore, they retained their bioactivity when incorporated into HA matrices of either molecular weight, but especially in HWM-HA, reinforcing its suitability as a functional delivery system targeting key drivers of abnormal wound healing. In summary, this work presents a novel therapeutic strategy that integrates Av-EVs and HMW-HA to target oxidative stress, inflammation, and fibrosis in a cell-free, plant-derived formulation. It also emphasizes the importance of source material and processing parameters in enhancing the potency and reproducibility of EVs. Together, these findings support the translational potential of standardized nanotherapeutic approaches for regenerative skin therapy and improved scar management in fibrosis-related conditions.

Publication Date

12-2025

Document Type

Dissertation

Student Type

Graduate

Degree Name

Mechanical and Industrial Engineering (Ph.D)

Department, Program, or Center

Industrial and Systems Engineering

College

Kate Gleason College of Engineering

Advisor

Karin Wuertz-Kozak

Advisor/Committee Member

Denis Cormier

Advisor/Committee Member

Thomas R. Gaborski

Comments

This thesis has been embargoed. The full-text will be available on or around 7/5/2026.

Campus

RIT – Main Campus

Download

Share

COinS