Optimización de soportes de Colágeno tipo I como un sistema de entrega controlada para un extracto de caléndula (Calendula officinalis).

Abstract

En Colombia existe la necesidad de desarrollar productos de ingeniería de tejidos de costo moderado que sean efectivos, seguros y estables para el tratamiento de pérdidas tejidos y órganos. El grupo de ingeniería de tejidos del departamento de Farmacia de la Universidad Nacional, ha desarrollado soportes de colágeno y tejidos artificiales que al ser usados como injerto en heridas de espesor parcial mejoran la regeneración de tejidos blandos. Una alternativa sencilla y menos costosa de tratamiento es asociar soportes de colágeno con un extracto de flores caléndula (Calendula officinalis), aceptado por el INVIMA como antioxidante y cicatrizante de uso tópico. En este trabajo se optimizaron los soportes de colágeno tipo I mediante la incorporación de micropartículas de gelatina-colágeno, modificación que aumento la capacidad de asociación con el extracto de C. officinalis de los soportes, mejoro la resistencia a la degradación enzimática y en estudios de liberación in vitro modifico el mecanismo de liberación de metabolitos secundarios que componen el extracto de C. officinalis.

Abstract. Aiming to develop acellular collagen type I matrices with an improved biological performance in the treatment of skin wounds, scaffolds were modified with microspheres and the subsequent loading of an extract of marigold Calendula officinalis -flower rich in polyphenols. These compounds have shown anti-inflammatory and antioxidant activities that are beneficial in wound healing processes. Microspheres made of poly(vinyl alcohol), gelatin and mixtures of poly(vinyl alcohol)-collagen and gelatin-collagen were produced by a water-in-oil emulsion/cross-linking method. Their morphology, size distribution, swelling rate and ability to associate with the extract were characterized. Gelatin-collagen microspheres swelled and showed the highest capacity to load the extract and thus, they were chosen to be incorporated into collagen suspensions at three growing concentrations (1.0 mg/mL, 2.5 mg/mL and 5.0 mg/mL) to manufacture collagen scaffolds including gelatin-collagen microspheres. Resistance to enzymatic degradation, ability to associate with the extract, and release profile of the three gelatin-collagen microsphere-scaffold prototypes were assessed, including scaffolds without microspheres as controls. Data indicated that gelatin-collagen microspheres increased the scaffolds' resistance to enzymatic degradation in vitro, as well as their association with the flower extract. Finally, the microspheres prolonged the release of the extract supporting their potential application in therapy of skin wounds.