Electrospun Fibers as a Dressing Material for Drug and Biological Agent Delivery in Wound Healing Applications

Wound healing is a complex tissue regeneration process that promotes the growth of new tissue to provide the body with the necessary barrier from the outside environment. In the class of non-healing wounds, diabetic wounds, and ulcers, dressing materials that are available clinically (e.g., gels and creams) have demonstrated only a slow improvement with current available technologies. Among all available current technologies, electrospun fibers exhibit several characteristics that may provide novel replacement dressing materials for the above-mentioned wounds. Therefore, in this review, we focus on recent achievements in electrospun drug-eluting fibers for wound healing applications. In particular, we review drug release, including small molecule drugs, proteins and peptides, and gene vectors from electrospun fibers with respect to wound healing. Furthermore, we provide an overview on multifunctional dressing materials based on electrospun fibers, including those that are capable of achieving wound debridement and wound healing simultaneously as well as multi-drugs loading/types suitable for various stages of the healing process. Our review provides important and sufficient information to inform the field in development of fiber-based dressing materials for clinical treatment of non-healing wounds.

Diabetes mellitus in Addis Ababa, Ethiopia: admissions, complications and outcomes in a large referral hospital

SETTING

The Black Lion Referral Hospital, Addis Ababa, Ethiopia.

OBJECTIVE

To document indications for admission, complications and outcomes of patients with diabetes mellitus (DM) admitted between 2010 and 2013.

DESIGN

A descriptive retrospective study using medical files.

RESULTS

Of 8048 admissions, 523 (6.5%) had DM; of these, 418 medical records were retrieved: 301 (72%) patients had type 2 and 104 (28%) type 1 disease, with male sex (62%) and older age (median age 60 years) being features of type 2 disease. Main admission diagnoses for type 2 disease were diabetic foot ulcer (39%) and cardiovascular disease (21%); for type 1 disease, it was diabetic ketoacidosis (62%). Hypertension, neuropathy, nephropathy, retinopathy and diabetic foot accounted for 85% of the 756 existing complications. Overall in-patient mortality was 21%. Of the 89 deaths, 77 occurred among patients with type 2 disease; the main indications for admission were diabetic foot ulcer/gangrene and cardiovascular disease.

CONCLUSION

DM, especially type 2 DM, is an important cause of admission to Ethiopia's largest referral hospital. Many patients had already developed disease-related complications at admission, and mortality was high. There is a need to improve awareness about and care for DM in Ethiopia.

The Role of Electrospun Fiber Scaffolds in Stem Cell Therapy for Skin Tissue Regeneration

Stem cell therapy has emerged as one of the topics in tissue engineering where undifferentiated and multipotent cells are strategically placed/ injected in tissue structure for cell regeneration. Over the years, stem cells have shown promising results in skin repairs for non-healing and/or chronic wounds. The addition of the stem cells around the wound site promotes signaling pathways for growth factors that regulate tissue reconstruction. However, injecting stem cells around the wound site has its drawbacks, including cell death due to lack of microenvironment cues. This particular issue is resolved when biomaterial scaffolds are involved in the cultivation and mechanical support of the stem cells. In this review, we describe the current models of stem cell therapy by injections and those that are done through cell cultures using electrospun fiber scaffolds. Electrospun fibers are considered as an ideal candidate for cell cultures due to their surface properties. Through the control of fiber morphology and fiber structure, cells are able to proliferate and differentiate into keratinocytes for skin tissue regeneration. Furthermore, we provide another perspective of using electrospun fibers and stem cells in a layer-by-layer structure for skin substitutes (dressing). Finally, electrospun fibers have the potential to incorporate bioactive agents to achieve controlled release properties, which is beneficial to the survival of the delivered stem cells or the recruitment of the cells. Overall, our work illustrates that electrospun fibers are ideal for stem cell cultures while serving as cell carriers for wound dressing materials.