{'fraction_non_alphanumeric': 0.028350515463917526, 'fraction_numerical': 0.011168384879725086, 'mean_word_length': 5.472222222222222, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 1, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Development of nanoparticulate drug delivery systems based on thiolated poly(acrylic acid)

In this study the preparation and stabilization of poly(acrylic acid)-cysteine nanoparticles and incorporation of a fluorescence marked model-compound was investigated. Nanoparticles were prepared by ionic gelation of a poly(acrylic acid)-cysteine conjugate with calcium chloride. Poly(acrylic acid)-cysteine nanoparticles display high cohesive properties due to a cross-linking process via calcium bridges in the core and the pervasive formation of disulphide bonds and were 139 ± 34 nm in size. Nanoparticles were loaded with FITC-dextrans (flourescein isothiocyanate-dextrans) of 4, 20 and 40 kDa molecular mass as model-compound via sonication method or via vibration method for 3 and 24 h. In vitro release studies showed an initial burst release followed by an extended release of model-compounds. The lower the molecular mass of the FITC-dextrans, the higher was the amount of incorporated and released model compounds. Vibration seems to be a proper method for the incorporation of hydrophilic and macromolecular drugs in poly(acrylic acid)-cysteine nanoparticles.