Photo-cross-linked hydrogels with polysaccharide-poly(amino acid) structure: new biomaterials for pharmaceutical applications.
The aim of this work has been the preparation and characterization of novel hydrogels with polysaccharide-poly(amino acid) structure having suitable physicochemical properties for pharmaceutical applications. In the first step, hyaluronic acid (HA) and alpha,beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) have been derivatized with methacrylic anhydride (AMA), thus obtaining HA-AMA and PHM derivatives, respectively. In the second step, aqueous solutions of both these derivatives have been irradiated at 313 nm to obtain chemical hydrogels. The hydrogel obtained by irradiating for 15 min an aqueous solution containing 4% w/v of HA-AMA and 4% w/v of PHM resulted in the highest yield. Its swelling ability was dependent on the pH and nature of the external medium. Besides, this hydrogel undergoes a partial hydrolysis, especially in the presence of enzymes, such as esterase or hyaluronidase, but the entity of this degradation is lower than that observed for a hydrogel based on HA-AMA alone. The ability of this hydrogel to entrap drug molecules has been evaluated by using thrombin as a model drug. In vitro release studies and a platelet aggregation test demonstrated that the HA-AMA/PHM hydrogel is able to release thrombin in the active form, thus suggesting its suitability for the treatment of hemorrhages.
Pitarresi
Giovanna
G
Dipartimento di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123 Palermo, Italy. giopitar@unipa.it
Pierro
Paola
P
Palumbo
Fabio S
FS
Tripodo
Giuseppe
G
Giammona
Gaetano
G
D000596:Amino Acids / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002626:Chemistry, Pharmaceutical; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry* / Q000528:radiation effects; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000737:chemistry*; D013997:Time Factors; D014466:Ultraviolet Rays
D000596:Amino Acids; D001672:Biocompatible Materials; D020100:Hydrogels; D011134:Polysaccharides