Nanofibres to deliver drugs to wounds

Currently, there is a growing demand for biomedical applications such as scaffolds for tissue engineering, wound healing dressing and other implantable wound healing, augmentation, and regeneration devices. Specifically these foams have been made from biocompatible polymers, which have an open celled microstructure.

The polymer used in this study was poly(lactide-co-glycolide) (PLAGA), and nanofibres of PLAGA were fabricated with the use of the electrospinning process, according to D S Katti and colleagues at the University of Virginia.

The study determined the effect of fabrication parameters, orifice diameter (needle gauge), polymer solution concentration and voltage per unit length, on the morphology and diameter of electrospun nanofibres.

In addition, the mass per unit area of the electrospun nanofibres as a function of time was determined and the feasibility of antibiotic (cefazolin) loading into PLAGA nanofibres was also studied.

This measurement is particularly important because chronic wounds have an imbalance of tissue formation and degradation and are impaired at the granulating phase of wound repair. In addition to this invention acting as a scaffold, it can facilitate the progression of wound healing by changing the environment in the wound.

Cell physiology is affected by environment, which may be affected by the scaffold in several ways, such as changing the availability of growth factors, moisture levels and physical interactions.

The results indicate that the diameter of PLAGA nanofibres decreased with an increase in needle gauge (decrease in orifice diameter), and increased with an increase in the concentration of the polymer solution, the researchers stated.

Feasibility of drug incorporation into the PLAGA nanofibres was demonstrated with the use of cefazolin, a broad-spectrum antibiotic. Overall, these studies demonstrated the PLAGA nanofibres can be tailored to desired diameters through modifications in processing parameters, and that antibiotics such as cefazolin can be incorporated into these nanofibres. Therefore, PLAGA nanofibres show potential as antibiotic delivery systems for the treatment of wounds, the researchers concluded.

This controlled method of delivering drugs is not a new concept. Methods have been developed to achieve the efficient delivery of a therapeutic drug to a mammalian body part requiring pharmaceutical treatment. Use of an aqueous liquid which can be applied at room temperature as a liquid but which forms a semi-solid gel when warmed to body temperature has been utilised as a vehicle for some drug delivery since such a system combines ease of application with greater retention at the site requiring treatment than would be the case if the aqueous composition were not converted to a gel as it is warmed to mammalian body temperature.

Katti and colleagues published their study in the Journal of Biomedical Materials Research.​ The study is entitled: 'Bioresorbable nanofibre-based systems for wound healing and drug delivery: Optimisation of fabrication parameters.'