Pharmacological treatment of wounds

Development of an insect metalloproteinase inhibitor drug carrier system for application in chronic wound infections

OBJECTIVES

The insect metalloproteinase inhibitor (IMPI) represents the first peptide capable of inhibiting virulence-mediating microbial M4-metalloproteinases and is promising as a therapeutic. The purpose of this study was to develop a suitable drug carrier system for the IMPI drug to enable treatment of chronic wound infections. Specifically, we studied on poloxamer 407 hydrogels, examining the influence of several additives and preservatives on the rheological parameters of the hydrogels, the bioactivity and release of IMPI.

METHODS

The rheological characterisation of the hydrogel was performed by oscillatory measurements. The bioactivity of IMPI was evaluated in a Casein fluoresence quenching assay.

KEY FINDINGS

In this study, a suitable application form for the dermal treatment of chronic wound infections with IMPI was designed. The influences of poloxamer 407 concentration and various additives on the viscoelastic properties and preservation of a thermosensitive hydrogel were investigated. The incorporation of the precursor drug IMPI-gluthathione-s-transferase (GST) in the hydrogel had no influence on the rheological characteristics and will be released. The bioactivity of IMPI-GST is not influenced by the hydrogel and remains constant over 4 weeks of storage.

CONCLUSIONS

This study reports the development of a poloxamer hydrogel as a suitable carrier system for the application of IMPI.

Nerve growth factor, human skin ulcers and vascularization. Our experience

Cutaneous wound is known to elicit a series of typical cellular responses that include clotting, inflammatory infiltration, reepithelialization, the formation of granulation tissue, including new blood vessel, followed by tissue remodeling and wound contraction. The regulatory molecules implicated in these events are not well known. Neurotrophins and their receptors are trophic factors that are known to play important roles in cutaneous tissues, nerve development and reconstruction after injury. Among the neurotrophins, the nerve growth factor (NGF) was one of the earliest used for clinical studies. NGF has been tested for potential therapeutic application in neuropathies of the central and peripheral nervous system and more recently in human corneal and cutaneous ulcers. Here, I present and discuss data obtained in the last few years on the healing action of NGF in human and domestic animal skin ulcers.