Drug-Free ROS Sponge Polymeric Microspheres Reduce Tissue Damage from Ischemic and Mechanical Injury

Area of Science:

• Biomaterials Science
• Nanotechnology
• Regenerative Medicine

Background:

• Reactive oxygen species (ROS) play a critical role in various pathologies, including diabetic peripheral arterial disease (PAD) and post-traumatic osteoarthritis (PTOA).
• Poly(propylene sulfide) (PPS) microspheres (MS) possess inherent antioxidant properties that warrant investigation for therapeutic applications.

Purpose of the Study:

• To evaluate the antioxidant capacity of PPS microspheres against different ROS.
• To explore the therapeutic efficacy of PPS microspheres in preclinical models of diabetic PAD and PTOA.

Main Methods:

• In vitro assays (cell-free and cell-based) were used to assess ROS scavenging by PPS microspheres.
• Mouse models of diabetic PAD and mechanically induced PTOA were employed to evaluate therapeutic benefits.
• Measurements included hind limb perfusion, vascular remodeling, matrix metalloproteinase (MMP) activity, and articular cartilage damage.

Main Results:

• PPS microspheres effectively scavenged hydrogen peroxide, hypochlorite, and peroxynitrite, but not superoxide.
• In diabetic PAD models, PPS-MS treatment improved hind limb ischemia recovery, indicated by increased hemoglobin saturation and perfusion.
• In PTOA models, PPS-MS reduced MMP activity and mitigated articular cartilage damage.

Conclusions:

• Local delivery of PPS microspheres demonstrates therapeutic potential by improving vascular response in ischemic injury associated with chronic hyperglycemia.
• PPS microspheres effectively reduce articular cartilage destruction following joint trauma.
• PPS microspheres represent a promising material for sustained local antioxidant therapy and drug delivery to inflamed tissues.