Domestic Speakers Webinar Series

Peripheral vascular occlusive disease is an emerging cardiovascular disease, consisting in the blockage of blood vessels in limbs due to atherosclerotic plaques, causing reduced blood flow with extensive limb pain, and disfunction, ulcerations and high risk of amputation. For the most severe cases, reperfusion through open by-bass surgery is required, using autologous vessel implants due to lack of small-diameter (< 6 mm) synthetic grafts with adequate patency and compliance characteristics. Infections are frequent complications in vascular surgery and are associated to a high risk of death. Their management requests total graft excision and wound debridement, leading to failure of the vascular reconstructive surgery procedure. Aim of this webinar is to propose a local drug delivery, tissue engineering combined approach to overcome these drawbacks: we developed a 2.5 mm diameter tubular graft prototype, loaded with tobramycin and functionalized with polyL lysin (PLL). The graft was obtained by electrospinning polylactide-co glycolide (PLGA) to obtain a biodegradable scaffold that should mimic the extracellular matrix, and through PLL good cell attachment and proliferation within 48 hours was achieved. Tobramycin was successfully encapsulated in the electrospun fibers, allowing its controlled release fo  the desired time span (7 days). In vitro antibacterial assays performed on S. aureus and E. coli showed an excellent microbicidal effect throughout the 5 days of testing.

Chronic wounds are the most traumatic and physically debilitating injuries that can lead to an aberrant healing response culminating with the formation of hypertrophic scars (HTSs). Early wound excision and skin grafting are common clinical practices that have significantly improved the outcomes for severe burn injured patients by reducing mortality rate and days of hospital stay. However, currently available skin grafts and skin substitutes are fraught with complications, often resulting in long-term physical and psychological sequel and this type of practices are not enough to constrain the insurgences of infection, pain, and in particular HTSs, that continue to remain the major challenge in wound healing research and management. For this reason, the aim of this work is to propose an advanced medicated dressing combining the fiber technology with the controlled release of and antifibrotic and antimicrobial agents to create an innovative non-invasive topical prophylactic treatment for HTSs. This treatment allows to modulate major factors involved in wound healing process, as TGF-β1, TGF-β1R1, type I Collagen, alpha 1 (COL1A1), TNF-α and (IL)-1β. In addition, this advanced dressing is designed to remain on the wound bed for 3 days ensuring a controlled release of encapsulated agents and avoiding further injuries to the newly formed granulation tissue during dressing changes.