Fully bio-based porous nanocomposite scaffolds based on nanocellulose and nanochitin were processed and characterized to explore the potential of these scaffolds in wound dressing and cartilage applications. The processing techniques involved electrospinning, freeze-drying and porogen leaching. Cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) were isolated from pure cellulose sources through chemical and mechanical treatments. Chitin nanocrystals (ChNCs) were isolated via acid hydrolysis procedure from crab shells.CNCs, CNFs and ChNCs were found to be cytocompatible and supported growth of adipose derived (ASCs) stem cells and L929 cell line indicating the potential use of these nanoparticles in biomedical applications. Randomly oriented nanocomposite fiber mats containing chitosan/PEO reinforced with CNCs and ChNCs were produced using electrospinning technique. The nanocrystals as well as crosslinking showed positive impact on the mechanical properties of electrospun mats. The nanocomposite mats showed porous structures, which can support cell growth and interconnectivity. The water vapor permeability results are in the range of 1202-1879 g.m2d-1which is in the range of water vapour transmission for wounds. So these nanocomposite mats are expected to have potential in wound dressing application.Porous scaffolds containing biopolymer matrix reinforced with cellulose nanofibers (CNFs) were prepared by freeze-drying or porogen leaching and were crosslinked to enhance mechanical and dimensional stability. Pore size in the range of 20-200 μm was obtained, which is expected to facilitate the cell growth and interconnectivity. The freeze-dried scaffolds showed suitable mechanical properties while no considerable improvement was achieved after crosslinking in PBS medium. Short-term cytocompatibility studies showed non-cytotoxicity of the scaffolds for human chondrocytes after 7 days cell culturing.Acknowledgements:Financial support from VINNOVA (No. 2011-02071) under MNT-ERANET project, n-POSSCOG is acknowledged. Jean-Michel Poirier and Florence Rinn are acknowledged for the cartilage.