[Show abstract][Hide abstract] ABSTRACT: A kind of chemically cross-linked pH-sensitive hydrogels based on methoxyl poly(ethylene glycol)-poly(caprolactone)-acryloyl chloride (MPEG-PCL-AC, PECA), poly(ethylene glycol) methyl ether methacrylate (MPEGMA, MEG), N,N-methylenebisacrylamide (BIS), and itaconic acid (IA) were prepared without using any organic solvent by heat-initiated free radical method. The obtained macromonomers and hydrogels were characterized by (1)H NMR and FT-IR, respectively. Morphology study of hydrogels was also investigated in this paper, and it showed that the hydrogels had good pH-sensitivity. The acute toxicity test and histopathological study were conducted in BALB/c mice. The results indicated that the maximum tolerance dose of the hydrogel was higher than 10000 mg/kg body weight. No morality or signs of toxicity were observed during the whole 7-day observation period. Compared to the control groups, there were no important adverse effects in the variables of hematology routine test and serum chemistry analysis both in male or female treatment group. Histopathological study also did not show any significant lesions, including heart, liver, lung, spleen, kidney, stomach, intestine, and testis. All the results demonstrated that this hydrogel was nontoxic after gavage. Thus, the hydrogel might be the biocompatible potential candidate for oral drug delivery system.
BioMed research international. 01/2013; 2013:239838.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to prepare PCL-PEG-PCL (PCEC) microspheres to protect camptothecin from hydrolysis, to extend its release time and to enhance its treatment efficacy on colorectal peritoneal carcinomatosis and tumor growth in mice. Camptothecin (CPT)-loaded PCL-PEG-PCL (PCEC) microspheres were prepared by oil-in-water emulsion solvent evaporation method. The particle size, morphological characteristics, encapsulation efficiency, in vitro drug release studies and in vitro cytotoxicity of CPT-loaded PCEC microspheres have been investigated. In vivo studies were carried out on Balb/c male mice bearing colorectal peritoneal carcinomatosis. CPT-loaded PCEC microspheres were applied to abdominal cavity of mice once a week. Free CPT was used as a positive control. On 14th day of treatment, mice were sacrificed and antitumor activities of CPT-loaded PCEC microspheres were evaluated. Compared with control group, a significant decrease in the number of tumor nodes was observed in group treated with CPT-loaded PCEC microspheres. Immunohistochemistry staining of tumor tissues with CD34 revealed that MVD positive cells were significantly reduced in CPT-loaded PCEC microspheres treated group in contrast to other groups (P<0.05). The CPT-loaded PCEC microspheres were considered potentially useful to treat the abdominal metastases of colon carcinoma.
Cancer letters 08/2011; 312(2):189-96. · 5.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this work, pH-sensitive P(CE-MAA-MEG) hydrogel coated with alginate-Ca2+ layer was successfully developed, which might be potential application for oral protein/vaccine delivery system. Morphology, swelling behavior, and in vitro release behavior of the alginate/P(CE-MAA-MEG) composite hydrogel were studied in detail. The results confirmed that the alginate/P(CE-MAA-MEG) composite hydrogel showed great pH-sensitivity. The fact that Bovine Serum Albumin (BSA) was released slowly in acidic environment while it was released quickly in neutral medium suggested that the composite hydrogel might be a candidate for protein drugs via oral administration.
[Show abstract][Hide abstract] ABSTRACT: In this work, a novel pH-sensitive hydrogels based on macromonomer of methoxyl poly(ethylene glycol)-poly(caprolactone)-acryloyl chloride (MPEG-PCL-AC, PCE-AC), poly(ethylene glycol) methyl ether methacrylate (MPEGMA), and methacrylic acid (MAA) were successfully synthesized by heat-initiated free radical polymerization method. The obtained macromonomers and hydrogels were characterized by (1)H NMR and FT-IR, respectively. Morphology study, swelling behavior, in vitro drug release behavior, acute oral toxicity of hydrogels, and cytotoxicity of PCE-AC macromonomer were also investigated in this paper. Finally, the hydrogels demonstrated that the sharp change in different pH value, thus believing to be promising the suitability of the candidate for oral drug-delivery systems.
International Journal of Pharmaceutics 04/2010; 389(1-2):130-8. · 3.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A series of biodegradable and pH-sensitive hydrogels based on poly(ε-caprolactone) (PCL), Pluronic, and methylacrylic acid (MAA) were successfully prepared by UV-initiated free radical polymerization, which were further characterized by 1H NMR and FTIR. Swelling behavior in different aqueous media and pH-responsibility of the hydrogels were studied in detail. With increase in pH value of aqueous media from 1.2 to 7.2, swelling ratio of the hydrogels increased accordingly. The hydrolytic degradation behavior of these hydrogels was also investigated in detail. The biodegradable pH-sensitive hydrogel obtained in this work might have great potential application in drug delivery system.
[Show abstract][Hide abstract] ABSTRACT: This paper prepared novel biodegradable and pH-sensitive microgels based on Poly(epsilon-caprolactone)-Pluronic-Poly(epsilon-caprolactone)-dimethacrylate (PCFC-DMA), Poly(ethylene glycol) dimethacrylate (PEG-DMA) and methylacrylic acid (MAA) cross-linked with N,N'-methylenebisacrylamide (BIS), initiated by NaHSO(3), K(2)S(2)O(8). The blank microgels were prepared by inversed-phase suspension polymerization method and pH sensitivity of microgels was characterized. Then the blank microgels were loaded with hydrophilic model drug vitamin-12 (VB-12) and in vitro drug release behaviour was also studied here.
Journal of Microencapsulation 11/2009; 26(7):642-8. · 1.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this work, a novel biodegradable pH-sensitive hydrogel based on poly(ɛ-caprolactone) (PCL), methoxpoly(ethylene glycol) (MPEG) and methacrylic acid (MAA) was prepared by UV-initiated free radical polymerization. The resulting macromonomers and hydrogels were characterized by FTIR and/or 1H NMR. Swelling behaviour and pH sensitivity of the hydrogels were studied in detail. With increase in pH of aqueous medium from 1.2 to 7.2, swelling ratio of the hydrogels increased accordingly. The hydrolytic degradation behaviour was also investigated. The prepared biodegradable pH-sensitive hydrogel based on PCL, MPEG, and MAA might have great potential application in smart drug delivery system.
[Show abstract][Hide abstract] ABSTRACT: A biodegradable sponge, composed of chitosan (CS) and sodium alginate (SA), was successfully obtained in this work. The sponge was ethereal and pliable. The chemical structure and morphology of the sponges was characterized by FTIR and SEM. The swelling ability, in vitro drug release and degradation behaviors, and an in vivo animal test were employed to confirm the applicability of this sponge as a wound dressing material. As the chitosan content in the sponge decreased, the swelling ability decreased. All types of the sponges exhibited biodegradable properties. The release of curcumin from the sponges could be controlled by the crosslinking degree. Curcumin could be released from the sponges in an extended period for up to 20 days. An in vivo animal test using SD rat showed that sponge had better effect than cotton gauze, and adding curcumin into the sponge enhanced the therapeutic healing effect.
BioMed Research International 01/2009; 2009:595126. · 2.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this paper, a novel biodegradable and pH/thermo-sensitive hydrogel based on poly(ɛ-caprolactone), methoxyl poly(ethylene glycol), methylacrylic acid and N-isopropylacrylamide was prepared by UV-initiated free radical polymerization. The hydrogels were characterized by Fourier transforms infrared ray. The thermal responsibility was investigated with the help of differential scanning calorimetry. Swelling behavior in aqueous medium with different pH value was studied in detail. When the pH value of the aqueous medium was increased from 1.2 to 7.2, the swelling ratio of the hydrogels increased accordingly. The morphology was observed by scanning electron microscopy, and the hydrolytic degradation behavior in different aqueous media (pH 1.2 and pH 7.2) was also investigated in detail. The prepared biodegradable pH/thermo-sensitive hydrogel based on poly(ɛ-caprolactone), methoxyl poly(ethylene glycol), methylacrylic acid and N-isopropylacrylamide hold great promise in the development of a smart drug delivery system.
Macromolecular Research 21(8). · 1.64 Impact Factor