Carbohydrate Polymers 99 (2014) 47–58 Contents lists available at ScienceDirect Carbohydrate Polymers jo ur nal homep age: www.elsevier.com/locate/carbpol PVA bio-nanocomposites: A new take-off using cellulose nanocrystals and PLGA nanoparticles N. Rescignano a , E. Fortunati b,∗ , S. Montesano c , C. Emiliani c , J.M. Kenny a,b , S. Martino c , I. Armentano b a Institute of Polymer Science and Technology, ICTP – CSIC, Madrid, Spain b Materials Engineering Center, UdR INSTM, Strada di Pentima 4, 05100 Terni, Italy c Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy a r t i c l e i n f o Article history: Received 2 July 2013 Received in revised form 19 August 2013 Accepted 22 August 2013 Available online 28 August 2013 Keywords: Bio-nanocomposite Poly(vinyl alcohol) Cellulose nanocrystals Stem cells a b s t r a c t The formation of a new generation of hybrid bio-nanocomposites is reported: these are intended at modulating the mechanical, thermal and biocompatibility properties of the poly(vinyl alcohol) (PVA) by the combination of cellulose nanocrystals (CNC) and poly (d,l-lactide-co-glycolide) (PLGA) nanoparti- cles (NPs) loaded with bovine serum albumin fluorescein isothiocynate conjugate (FITC-BSA). CNC were synthesized from microcrystalline cellulose by hydrolysis, while PLGA nanoparticles were produced by a double emulsion with subsequent solvent evaporation. Firstly, binary bio-nanocomposites with differ- ent CNC amounts were developed in order to select the right content of CNC. Next, ternary PVA/CNC/NPs bio-nanocomposites were developed. The addition of CNC increased the elongation properties without compromising the other mechanical responses. Thermal analysis underlined the nucleation effect of the synergic presence of cellulose and nanoparticles. Remarkably, bio-nanocomposite films are suitable to vehiculate biopolymeric nanoparticles to adult bone marrow mesenchymal stem cells successfully, thus representing a new tool for drug delivery strategies. © 2013 Elsevier Ltd. All rights reserved. 1. Introduction There is a growing interest in drug delivery systems that can provide site-specific and continuous therapeutic drug levels for extended periods of time. These systems can been visioned as adhe- sive patches or implantable devices (Rescignano et al., 2013). Poly(vinyl alcohol) (PVA) is the largest synthetic water-soluble polymer produced in the world (Ding et al., 2002). It is a hydrophilic and biocompatible synthetic polymer and it has been widely used in different areas of the biotechnological and biomedical fields due to its excellent chemical and physical properties, easy processing technique and low cytotoxicity (Chiellini, Corti, D’Antone, & Solaro, 2003). PVA is a highly versatile polymer offering a wide spectrum of property profiles opening the way of using it in a broad field of applications, among which is their use as a matrix for biodegradable composites. The nanocomposite approach has emerged in the last two decades as an efficient strategy to upgrade the structural and functional properties of synthetic polymers. Generally, polymer nanocomposites are the result of the combi- nation of polymers and inorganic/organic fillers at the nanometer scale (Armentano et al., 2013; Armentano, Dottori, Fortunati, ∗ Corresponding author. Tel.: +39 0744 492921; fax: +39 0744 492950. E-mail address: elena.fortunati@unipg.it (E. Fortunati). Mattioli, & Kenny, 2010). A large variety of nanocomposites have been prepared using PVA as a matrix and nano-reinforcement such as layered silicate, silica, cadmium sulfide nanoparticles and car- bon nanotubes (Guo, Ma, Hu, & Jiang, 2007; Paiva et al., 2004; Strawhecker & Manias, 2000; Wang, Ding, & Cheng, 2007). Nor- mally, nanofillers used to prepare nanocomposites are inorganic and their processability, biocompatibility and biodegradability are much more limited than it is the case with those of organic nature (Armentano et al., 2010, 2013). Moreover, the use of cellulose nanocrystals (CNC) is increasing as the load-bearing constituent in developing new and inexpensive biodegradable materials due to their high aspect ratio. CNC have many additional advantages including a positive ecological effect, low density, low-energy con- sumption in manufacturing, ease for recycling by combustion, high sound attenuation and comparatively easy processability due to their non abrasive nature, which allows high filling levels, in turn resulting in significant cost savings. Moreover, CNC can be extracted from a wide variety of natural sources available throughout the world. The announcement of using cellulose nanocrystals from tunicin cellulose (structures from animal sources) as a reinforc- ing phase in a matrix, was firstly reported by Favier, Chanzy, and Cavaille (1995); the use of CNC from various sources such as ramie (Habibi & Dufresne, 2008), potato and starch (Dufresne, Cavaillé, & Helbert, 1997; Dufresne, Dupeyre, & Vignon, 2000), cotton and wood for the preparation of high performance composites has been 0144-8617/$ – see front matter © 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.carbpol.2013.08.061