Macromolecular Research, Vol. 23, No. 7, pp 636-648 (2015) www.springer.com/13233 pISSN 1598-5032 eISSN 2092-7673 636 © The Polymer Society of Korea and Springer 2015 Electrospun Scaffolds of Polylactide with a Different Enantiomeric Content and Loaded with Anti-Inflammatory and Antibacterial Drugs Elena Llorens 1 , Luis J. del Valle * ,1,2 , and Jordi Puiggalí 1,2 1 Departament d'Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028, Spain 2 Center for Research in Nano-Engineering (CrNE), Universitat Politècnica de Catalunya, Edifici C, C/Pasqual i Vila s/n, Barcelona E-08028, Spain Received February 9, 2015; Revised April 14, 2015; Accepted April 29, 2015 Abstract: Polylactide (PLA) electrospun microfibers were prepared and loaded with triclosan (TCS), ketoprofen (KTP), or their combination to obtain multifunctional scaffolds with bactericide and anti-inflammatory properties. Continuous and porous fibers with diameters in the micrometer scale and a unimodal distribution were successfully attained using a dual-electrospinning technique. Dual drug-loaded scaffolds showed a peculiar release that was in contrast to the single drug-loaded systems, which suggested the establishment of intermolecular interactions that delayed TCS and KTP release. Antimicrobial activity of all TCS-loaded electrospun scaffolds was demonstrated against E. coli and M. luteus bacteria; and furthermore, KTP-loaded samples slightly showed bactericide activity. Bio- compatibility of scaffolds was evaluated by adhesion and proliferation assays, and interestingly, the dual drug-load systems were able to support high TCS doses without adverse effects. Keywords: biomaterials, electrospinning, dual drug-release, polylactide, bactericide, triclosan, ketoprofen. Introduction Polylactide (PLA) is currently one of most attractive bio- degradable polymers because it is derived from renewable resources, can be easily processed and has many applications ranging from commodity to specialty uses. 1-5 PLA is gaining special attention in the biomedical field. Specifically, devices including degradable sutures, drug releasing micro/nanopar- ticles, and porous scaffolds for cellular applications can be mentioned. 6-10 The great advantages of PLA are due in part to its ability to degrade into the naturally occurring metabolite lactic acid under physiological conditions, but other exceptional qualities, like biocompatibility, FDA approval for clinical use, low immunogenicity and good mechanical properties must also be considered. PLA can be obtained by ring opening polymerization of L-lactide and/or D-lactide, a process that allows obtaining a large number of stereo-copolymers by changing their L/D ratio. Properties of PLA are strongly dependent on its optical purity; for example, PLA can range from semicrystalline to completely amorphous. 11 The degree of crystallinity and even molecular orientation also has a strong influence on PLA biodegradability; specifically, the selection of adequate pro- cessing conditions is important to achieve a specific orientation for a given stereoregularity. For example, Lee et al. concluded that molecular orientation in amorphous PLA increased with decreasing stretching temperature whereas semicrystalline samples required increasing temperatures. 12 It seems that, for amorphous samples, the most important effect concerns the highest possible orientation when molecular relaxation is hindered by a temperature decrease. For semicrystalline samples, the orientation phenomenon involves the deformation of formed spherulites, and consequently higher temperatures are needed. Electrospinning is currently one of the simplest methods to draw nano and microfibers from a polymer solution. Basically, the surface tension of a liquid droplet can be counteracted by the electrostatic repulsion due to the charging of the body of the liquid by a sufficiently high voltage. The droplet is stretched and may form a liquid jet if its molecular cohesion is suffi- ciently high. 13 Scaffolds prepared by electrospinning showed particularly good potential for drug delivery applications due to their large surface area and interconnected pore struc- ture. 14,15 Moreover, drug release behavior can be easily con- trolled by the morphology and composition of fibers. 16,17 Drug-loaded electrospun scaffolds can also be easily fabricated into various shapes (e.g. membranes or tubes) for different applications, such as wound dressing and nerve conduits. 18,19 To date, most studies of electrospun scaffolds for drug delivery have been focused on sustained release of a single drug. However, it is clear that the use of different drugs is a promising strategy that allows combination therapy and may even induce DOI 10.1007/s13233-015-3082-5 *Corresponding Author. E-mail: luis.javier.del.valle@upc.edu