IntroductionProcessingof ultrafine continuous polymeric fibers ranging from tensof nanometers to a few micrometers using electtrospinning techniqueis well known1. In recent years, nanosized reinforcements have been usedto further improve/ tailor the mechanical properties and structural morphologyof electrospun fibers2. The current study is aimed to developrandomly oriented nanocomposite fiber mats by electrospinning,using cellulose and chitin nanocrystals as reinforcements3/ functionaladditives and explore the potential of the electrospun nanofiber mats for wounddressing application.Materials and methodsElectrospinning of chitosan solution in aceticacid (50%) was carried out at 25 kV, gap distance of 155mm, flow rate13 mL/h. Cellulose nanocrystal (CNCs) having diameters of5-10 nm were isolated from microcrystalline cellulose (MCC) by63% sulphuric acid hydrolysis using Bondeson et alprocedure3.Chitin nanocrystals (ChNCs) were produced from crab shells by HClhydrolysis. The concentrations of nanocrystals in all themats were kept at 50%. The spinning solution used was a mixture of1:1 (w/w) of chitosan-PEO in 50 wt% aqueous acetic acid, with a3 wt% total polymer concentration. The mats werefurther crosslinked using genipin in order to improvemechanical properties.Results and discussionCNCs and ChNCs werefound to be biocompatible and supported growth of adiposederived stem cells (ASC) and L929 cell line indicating thatthese nanomaterials are potential reinforcements/ functional additivesfor biomedical products. Randomly oriented nanofiber mats wereprepared and the effect of inclusion of CNCs and ChNCs on the structuralmorphology and diameter of electrospun nanofiber werestudied. Crosslinking of the mats resulted in more compact film likestructure for only matrix (M) and M-CNCH2SO4 while M-ChNC and MCNCHCLmats wereless affected. The electrospun fibers had diameters in the range of116-631 nm, which decreasedwith inclusion of nanocrystals except for M-CNCH2SO4 whereaggregation of CNCs probably occurred. The nanocrystals as well asthe crosslinking had positive impact on the mechanicalproperties of electrospun mats. The random mats showed porosity andare expected to facilitate cell growth, though porosity decreasedwith crosslinking probably due to dissolution of PEO. The matsexhibited water vapour permeability in the range of 1202-1879 g.m2day-1, which falls in the range of water vapour transmissionfor wounds and the permeability decreased slightlyafter crosslinking. ConclusionsRandomlyoriented nanofiber electrospun mats were successfully producedfrom chitosan/ PEO blend reinforced with CNCs orChNCs. Electrospun porous random mats reinforced withChNCs are the most promising materials (fibers free of defects).The crosslinking had positive impact on mechanicalstrength where as porosity and water vapour transmissiondecreased after crosslinking. The porous morphology of the matsfacilitated cell growth and water vapour transmission and is expectedto have potential application as wound healing materials. Acknowledgments Financial support fromVINNOVA (No. 2011-02071) under MNT-ERANET project, n-POSSCOG isacknowledged. EDUCELL, Slovenia and CSIR, S. Africa are acknowledgedfor biocomatibility studies and water vapour transmissionstudies respectievely.  References1. Son, W.K.; Youk,J.H. et al . J. Poly Sci. , 2004, 42 (1), 5-11.2. Oksman, K.;Mathew, A.P.; Sain, M., Plastics, Rubber &Composites, 2009, 38, 396-405.3. Bondeson, D.;Mathew, A. P.; Oksman, K. Cellulose, 2006,13, 171- 180.  Proceeding of the MiMeOctober 8-11, 2013 - Faenza, Italy1st InternationalConference on Materials in Medicine