ABSTRACT
Objective: This study involves the synthesis of Gum tragacanth (gt) based interpenetrating polymer network (ipn) and its utilization for sustained release of anti-ulcerative drug i.e. pantoprazole sodium. Methods: IPN was synthesized from Gum tragacanth, polyacrylic acid (gt-cl-paa) hydrogel. gt-cl-paa was kept in distilled water. Further, acryamide (aam) and methylmethacrylate (mma) was added and then kept for overnight. Later on, lipase and glutaraldehyde were added. Homopolymers and the unreacted monomers were removed using acetone. Synthesized IPN was dried at 50 °C for further study. Synthesized ipn was swelled in water and the drug was added to it. The drug was entrapped in the pores of the synthesized ipn and then drug release behavior was studied using uv-vis spectrophotometer. Results: Gt, paa and mma based crosslinked IPN were synthesized using lipase-glutaraldehyde as initiator-crosslinker system. The synthesized IPN was pH sensitive and possessed the desired swelling capacity required for the controlled and systematic liberation of pantoprazole sodium at 37 °C. The kinetic of drug release was studied and found that lateral diffusion (DL) of drug was higher as compared to the initial diffusion (DI). The prepared IPN can be used as prospective carrier for prolonged drug delivery. Conclusion: A novel pH sensitive and colon targeted IPN was synthesized. It acts as an effective device for the controlled release of drug pantoprazole sodium.
ABSTRACT
OBJECTIVE: To design nanogels with different phase transition speeds and screen embolization and drug delivery materials that can be used for transcatheter arterial chemoembolization (TACE). METHODS: Random copolymer PNA nanogels and interpenetrating polymer PNA-IPN nanogels, in which the ratio of co-monomers between N-isopropylacrylamide (NIPAM) and acrylic acid (AA) were 3∶1, 2∶1 and 1∶1, respectively, were prepared by emulsion polymerization. The embolization and drug-loaded capacities of nanogels were evaluated by characterization of their particle morphology, temperature sensitivity, solution phase transition behavior and rheological properties. RESULTS: Nanogel particles were relatively uniform spheres. The particle size of PNA was 386-795 nm, and the particle size of PNA-IPN was 367-750 nm. The increase of temperature led to the decrease of particle size, while the increase of the ratio of the co-monomer AA caused the decrease of temperature sensitivity and gel strength of nanogels, and the increase of the phase transition temperature and the gelation speed. Compared with PNA, PNA-IPN-2 had slightly smaller particle size, lower gelation temperature, faster gelation speed and significantly increased gel strength. The PNA-IPN-2 could load doxorubicin by charge action with 10.3% of loading efficiency. CONCLUSION: The 140 mg•mL-1 PNA-IPN-2 solution has suitable gelation temperature, gelation speed and gel strength. The shearthinning nature and drug release feature are very favorable for TACE, so the PNA-IPN-2 solution is promising for the applications in TACE as nanogels embolization and drug delivery materials.
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The objective of this study was to carry out taste masking of ofloxacin (Ofl) by ion exchange resins (IERs) followed by sustained release of Ofl by forming interpenetrating polymer network (IPN) beads. Drug-resin complexes (DRCs) with three different ratios of Ofl to IERs (1:1, 1:2, 1:4) were prepared by batch method and investigated for in vivo and in vitro taste masking. DRC of methacrylic acid-divinyl benzene (MD) resin and Ofl prepared at a ratio of 1:4 was used to form IPN beads. IPN beads of MD 1:4 were prepared by following the ionic cross-linking method using sodium carboxymethyl xanthan gum (SCMXG) and SCMXG-sodium carboxymethyl cellulose (SCMXG-SCMC). IPN beads were characterized with FT-IR and further studied on sustained release of Ofl at different pH. In vivo taste masking carried out by human volunteers showed that MD 1:4 significantly reduced the bitterness of Ofl. Characterization studies such as FT-IR, DSC, P-XRD and taste masking showed that complex formation took place between drug and resin. In vitro study at gastric pH showed complete release of drug from MD 1:4 within 30 min whereas IPN beads took 5 h at gastric pH and 10 h at salivary pH for the complete release of drug. As the crosslinking increased the release kinetics changed into non-Fickian diffusion to zero-order release mechanism. MD 1:4 showed better performance for the taste masking of Ofl and IPNs beads prepared from it were found useful for the sustained release of Ofl at both the pH, indicating a versatile drug delivery system.
ABSTRACT
Background The tissue-engineered cornea is becoming the hot spot in the ophthalmologic field,while the research of corneal substitute is in the ascendant,because it is more similar to the corneal morpha and easy to survive in vivo.Objective This study was to investigate the biocompatibility of recombinant human type-Ⅲ collagen/poly9 ( 3-( methacryloylamino ) propyl dimethyl ( 3-sulfopropyl ) ammonium hydroxide ) ( PMPDSAH ) interpenetrating polymer network (IPN) (RHC-Ⅲ/PMPDSAH IPN) hydrogel as a tissue-engineered cornea in rabbit eye and its feasibility as the corneal substitute.Methods One hundred and eight rabbits were randomly divided into experimental group( 90 rabbits) and normal control group ( 3 rabbits),and 15 rabbits ( 30 eyes ) used as the donor corneas.RHC-Ⅲ/PMPDSAH IPN,NGF PMPDSAH IPN and corneal grafts were lamellarly transplanted into the right eyes in RHC-Ⅲ/PMPDSAH IPN group,NGF PMPDSAH IPN group and allograft group respectively.The corneal transparency and neovascularization were examined and scored under the slim lamp and compared among three groups using Kraskal-Wallis H test.The corneal epithelization time was observed and compared among these three groups using one way analysis of variance and LSD-t test.The histological examination of corneas was performed at the 3rd day,1st and 2nd week,1 st,3rd and 6th month after the surgery.The immunohistochemistry was used to detect the expression of K3 in cornea at the 6th month.Results The grafts were well attached in RHC-Ⅲ/PMPDSAH IPN group,NGF PMPDSAH IPN group and allograft group,and no rejection reaction was found throughout 6-month following up.Compared with normal control group,no significant differences were found in the scores of corneal opacification and neovescularization in these three groups (x2 =4.34,P =0.23 ;x2 =2.60,P =0.46 ) at the 6th month.NGF PMPDSAH IPN group achieved reepithelialization in (4.97±0.63) days and was obviously shorted than that in RHC-Ⅲ/PMPDSAH IPN group and allograft group ( t =11.97,P =0.00; t =5.80,P =0.00).The re-epithelialization time in RHC-Ⅲ/PMPDSAH IPN was (6.86±0.71) days,and that of allograft group was (5.87±0.43 ) days,showing a significant difference ( t =6.32,P =0.00).Hematoxylin-eosin staining results demonstrated that implanted materials integrated into the host corneal tissue well and support corneal epithelialization.Part of the material degraded at the 2nd week and degraded completely 1 month later.Regular alignment and distribution of collagen fibers were seen in the regenerated cornea and were similar to those of the normal stroma in 6 months.Immunohistochemistry showed the positive expression of keratin-3 in corneal epithelial cells.Conclusions RHC-Ⅲ/PMPDSAH IPN has a good biocompatibility without toxicity to corneal tissue.Furthermore,NGF can promote the corneal wound-healing and re-epithelialization.The material can be used as safe and reliable corneal substitute after improving the mechanical strength.