title: Interpenetrating polymer network (IPN) nanogels based on gelatin and poly(acrylic acid) by inverse miniemulsion technique: synthesis and characterization.
abstract: Novel interpenetrating polymer network (IPN) nanogels composed of poly(acrylic acid) and gelatin were synthesised by one pot inverse miniemulsion (IME) technique. This is based on the concept of nanoreactor and cross-checked from template polymerization technique. Acrylic acid (AA) monomer stabilized around the gelatin macromolecules in each droplet was polymerized using ammonium persulfate (APS) and tetramethyl ethylene diamine (TEMED) in 1:5 molar ratio and cross-linked with N,N-methylene bisacrylamide (BIS) to form semi-IPN (sIPN) nanogels, which were sequentially cross-linked using glutaraldehyde (Glu) to form IPNs. Span 20, an FDA approved surfactant was employed for the formation of homopolymer, sIPN and IPN nanogels. Formation of stable gelatin-AA droplets were observed at 2% surfactant concentration. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) studies of purified nanogels showed small, spherical IPN nanogels with an average diameter of 255 nm. In contrast, sIPN prepared using the same method gave nanogels of larger size. Fourier-transform infrared (FT-IR) spectroscopy, SEM, DLS, X-ray photoelectron spectroscopy (XPS) and zeta potential studies confirm the interpenetration of the two networks. Leaching of free PAA chains in sIPN upon dialysis against distilled water leads to porous nanogels. The non-uniform surface of IPN nanogels seen in transmission electron microscopy (TEM) images suggests the phase separation of two polymer networks. An increase of N/C ratio from 0.07 to 0.17 (from PAA gel to IPN) and O/C ratio from 0.22 to 0.37 (from gelatin gel to IPN) of the nanogels by XPS measurements showed that both polymer components at the nanogel surface are interpenetrated. These nanogels have tailoring properties in order to use them as high potential drug delivery vehicles for cancer targeting.
authors.affiliation: Centre for Biomedical Engineering, Indian Institute of Technology, 110016 New Delhi, India. rajaiitd@gmail.com
authors.forename: Veena
authors.initials: V
authors.lastname: Koul
authors.forename: Raja
authors.initials: R
authors.lastname: Mohamed
authors.forename: Dirk
authors.initials: D
authors.lastname: Kuckling
authors.forename: Hans-Jürgen P
authors.initials: HJ
authors.lastname: Adler
authors.forename: Veena
authors.initials: V
authors.lastname: Choudhary
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry; D005780:Gelatin / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D000080385:Nanogels; D036103:Nanotechnology; D010316:Particle Size; D011092:Polyethylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry*; D011094:Polyethyleneimine / Q000138:chemical synthesis* / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; D004655:Emulsions; D000080385:Nanogels; C413692:polyethylene glycol polyethyleneimine nanogel; D011092:Polyethylene Glycols; C006903:carbopol 940; D005780:Gelatin; D011094:Polyethyleneimine