RESUMEN
Among the natural macromolecules potentially used as the scaffold material in hydrogels, xylan has aroused great interest in many fields because of its biocompatibility, low toxicity, and biodegradability. In this work, new pH and thermoresponsive hydrogels were prepared by the cross-linking polymerization of maleic anhydride-modified xylan (MAHX) with N-isopropylacrylamide (NIPAm) and acrylic acid (AA) under UV irradiation to form MAHX-g-P(NIPAm-co-AA) hydrogels. The pore volume, the mechanical properties, and the release rate for drugs of hydrogels could be controlled by the degree of substitution of MAHX. These hydrogels were characterized by swelling ability, lower critical solution temperature (LCST), Fourier-transform infrared (FTIR), and SEM. Furthermore, the cumulative release rate was investigated for acetylsalicylic acid and theophylline, as well as the cytocompatibility MAHX-based hydrogels. Results showed that MAHX-based hydrogels exhibited excellent swelling-deswelling properties, uniform porous structure, and the temperature/pH dual sensitivity. In vitro, the cumulative release rate of acetylsalicylic acid for MAHX-based hydrogels was higher than that for theophylline, and in the gastrointestinal sustained drug release study, the acetylsalicylic acid release rate was extremely slow during the initial 3 h in the gastric fluid (24.26%), and then the cumulative release rate reached to 90.5% after sustained release for 5 h in simulated intestinal fluid. The cytotoxicity experiment demonstrated that MAHX-based hydrogels could promote cell proliferation and had satisfactory biocompatibility with NIH3T3 cells. These results indicated that MAHX-based hydrogels, as new drug carriers, had favorable behavior for intestinal-targeted drug delivery.
RESUMEN
OBJECTIVE: To compare the difference in the therapeutic effect on post-infectious cough differentiated as wind-cold retention in the lung between the combined therapy of scraping and xuanfei zhisou decoction and the simple application of xuanfei zhisou decoction. METHODS: Eighty patients were randomized into a combined therapy group and a Chinese herbal medicine group, 40 cases in each one. In the Chinese herbal medicine group, the oral administration of xuanfei zhisou decoction was used. The main ingredients included roasted herba ephedrae, amygdalus communis vas, rhizoma zingiberis recens, platycodon grandiflorum, flos farfarae, pinellia temata, radix stemonae, herba periliae, etc., one dose a day, twice a day. In the combined therapy group, on the basis of the treatment as the Chinese herbal medicine group, scraping therapy was added and applied to the bladder meridian of foot-taiyang, the lung meridian of hand-taiyin, the conception vessel and the governor vessel, focusing on Tiantu (CV 22), Baihui (GV 20), Dazhui (GV 14), Feishu (BL 13), Fengmen (BL 12), Taiyuan (LU 9), Lieque (LU 7) and Fengchi (GB 20), once a week and one-week treatment as one session. Totally, the continuous two sessions were required in the two groups. The cough symptom score, cough remission time, relapse, TCM syndrome score, the score of Leicester cough questionnaire (LCQ), SP concentration in the supernatant of the induced sputum before and after treatment as well as clinical efficacy were observed in the two groups. RESULTS: The cough symptom score, TCM symptom score and SP concentration in the supernatant of the induced sputum were all apparently reduced after treatment in the patients of the two groups (all P<0.01). The scores in the combined therapy group were reduced in the higher amplitude as compared with those in the Chinese herbal medicine group (all P<0.01). The total effective rate was 95.0% (38/40) in the combined therapy group, better than 87.5% (35/40) in the Chinese herbal medicine group (P<0.05). Regarding the cough remission time and relapse rate, the results in the combined therapy group were better than those in the Chinese herbal medicine group[(5.3±1.2) d vs (7.4±1.5) d, P<0.01; 0% (0/19) vs 62.5% (5/8), P<0.01]. The scoreo of LCQ was all apparently improved in the patients of the two groups (both P<0.01), and the score in the combined therapy group was higher than that in the Chinese herbal medicine group (P<0.01). CONCLUSIONS: Scraping therapy combined with xuanfei zhisou decoction and the simple application of xuanfei zhisou decoction all relieve the symptoms of post-infectious cough and improves the living quality. The therapeutic effects of the combined therapy are superior to the oral administration of xuanfei zhisou decoction.
