Calandrelli L, De Rosa G, Errico M E, La Rotonda M I, Laurienzo P, Malinconico M, Oliva A, Quaglia F
Istituto di Chimica e Tecnologia dei Polimeri (I.C.T.P.), C.N.R., c/o comprensorio ex-Olivetti, Fabbricato 70, Via Campi Flegrei 34, 80078 Pozzuoli, Napoli, Italy.
J Biomed Mater Res. 2002 Nov;62(2):244-53. doi: 10.1002/jbm.10138.
This study describes the synthesis of novel biodegradable graft copolymers based on a backbone of poly (L-lactic acid) (PLLA) on which short blocks of polyacrylamide (PAcr) were grafted. Preliminary results of their potential in the field of controlled-release technologies also have been reported. The copolymers have been synthesized through the radical polymerization of acrylamide initiated by a peroxide in the presence of PLLA. Two different methodologies of synthesis, namely, in solution and in emulsion, have been tested. The structure of the copolymers was studied by (1)H-NMR and infrared spectroscopy and by differential scanning calorimetry (DSC) and cytotoxicity tests were conducted to assess their biocompatibility. The copolymers were used to prepare particles by the emulsion-solvent evaporation technique. The shapes and dimensions of the particles were dependent on the polymer type and concentration used. The surfaces of the particles were modified by the presence of polyacrylamide residues, as demonstrated by zeta-potential measurements. The release behavior of the particles was assessed by encapsulating rhodamine B as the model compound. The release was faster for the particles prepared by the grafted polymer as a consequence of its increased hydrophilicity. Based on these novel biomaterials, preliminary results suggest a potential of the particles for peroral or parenteral drug delivery.
本研究描述了基于聚（L-乳酸）（PLLA）主链合成新型可生物降解接枝共聚物的过程，在该主链上接枝了短链聚丙烯酰胺（PAcr）。还报道了它们在控释技术领域潜力的初步结果。共聚物是通过在PLLA存在下用过氧化物引发丙烯酰胺的自由基聚合反应合成的。测试了两种不同的合成方法，即溶液法和乳液法。通过（1）H-NMR、红外光谱、差示扫描量热法（DSC）研究了共聚物的结构，并进行了细胞毒性测试以评估其生物相容性。通过乳液-溶剂蒸发技术使用共聚物制备颗粒。颗粒的形状和尺寸取决于所用聚合物的类型和浓度。如通过zeta电位测量所证明的，颗粒表面因聚丙烯酰胺残基的存在而被改性。通过将罗丹明B作为模型化合物进行包封来评估颗粒的释放行为。由于接枝聚合物亲水性增加，其制备的颗粒释放速度更快。基于这些新型生物材料，初步结果表明颗粒在口服或肠胃外给药方面具有潜力。
