Solid tumor chemotherapy using injectable gelatin microspheres containing free methotrexate and conjugated methotrexate

Narayani, Raj I.; Rao, K. Panduranga

doi:10.1016/0378-5173(96)04650-9

Cited by 18 publications

(4 citation statements)

References 19 publications

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“…The cross-links are based on aldehyde formation and condensation involving specific peptidyl lysine and hydroxylysine residues . For reconstituted collagen scaffolds, several physical and chemical cross-linking methods have been reported. − In comparison of all methods, the cross-linking of collagen with a carbodiimide is considered to be efficient and less harmful since the combination of carbodiimide with N-hydroxysuccinimide (NHS) results in the formation of amides between collagen molecules, and all excess residues can be removed . Collagen scaffolds cross-linked with carbodiimide can support the growth of fibroblasts, smooth muscle cells and periodontal ligament cells. − …”

Section: Introductionmentioning

confidence: 99%

Biomimetic Mineralization of Woven Bone-Like Nanocomposites: Role of Collagen Cross-Links

et al. 2011

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Ideal biomaterials for bone grafts must be biocompatible, osteoconductive, osteoinductive and have appropriate mechanical properties. For this, the development of synthetic bone substitutes mimicking natural bone is desirable, but this requires controllable mineralization of the collagen matrix. In this study, densified collagen films (up to 100 μm thick) were fabricated by a plastic compression technique and cross-linked using carbodiimide. Then, collagen-hydroxyapatite composites were prepared by using a polymer-induced liquid-precursor (PILP) mineralization process. Compared to traditional methods that produce only extrafibrillar hydroxyapatite (HA) clusters on the surface of collagen scaffolds, by using the PILP mineralization process, homogeneous intra- and extrafibrillar minerals were achieved on densified collagen films, leading to a similar nanostructure as bone, and a woven microstructure analogous to woven bone. The role of collagen cross-links on mineralization was examined and it was found that the cross-linked collagen films stimulated the mineralization reaction, which in turn enhanced the mechanical properties (hardness and modulus). The highest value of hardness and elastic modulus was 0.7 ± 0.1 and 9.1 ± 1.4 GPa in the dry state, respectively, which is comparable to that of woven bone. In the wet state, the values were much lower (177 ± 31 and 8 ± 3 MPa) due to inherent microporosity in the films, but still comparable to those of woven bone in the same conditions. Mineralization of collagen films with controllable mineral content and good mechanical properties provide a biomimetic route toward the development of bone substitutes for the next generation of biomaterials. This work also provides insight into understanding the role of collagen fibrils on mineralization.

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Section: Introductionmentioning

confidence: 99%

Biomimetic Mineralization of Woven Bone-Like Nanocomposites: Role of Collagen Cross-Links

et al. 2011

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“…The development of new drug dosage forms focuses on enhanced bioavailability, greater efficiency, lower toxicity, and controlled release (Narayani & Panduranga, 1996;Esposito et al, 1966;Cortesi et al, 1998;Wei et al, 2008;Fischer et al, 2009;Vivero-Escoto et al, 2009). Recently, mesoporous materials become one of hotspots in the drug delivery systems, especially as implantable local-delivery devices for bone tissue repair (ValletRegí et al, 2007;Manzano & Vallet-Regi, 2010).…”

Section: Introductionmentioning

confidence: 99%

In vivodrug release and antibacterial properties of vancomycin loaded hydroxyapatite/chitosan composite

Zhang

Wang

et al. 2012

Drug Delivery

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“…No new bands were detected in the spectra of chitosan-gelatin sponge indicating no interaction between drug and chitosan-gelatin matrix. Prolongation of drug release has been reported when a polymer-drug conjugate occurred (Narayani & Reo, 1993;Narayani & Reo, 1996).…”

Section: Ft-ir Spectroscopymentioning

confidence: 98%

Implantable Biodegradable Sponges: Effect of Interpolymer Complex Formation of Chitosan With Gelatin on the Release Behavior of Tramadol Hydrochloride

Foda

El-Laithy

Tadros

2007

Drug Development and Industrial Pharmacy

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The effect of interpolymer complex formation between positively charged chitosan and negatively charged gelatin (Type B) on the release behavior of tramadol hydrochloride from biodegradable chitosan-gelatin sponges was studied. Mixed sponges were prepared by freeze-drying the cross-linked homogenous stable foams produced from chitosan and gelatin solutions where gelatin acts as a foam builder. Generation of stable foams was optimized where concentration, pH of gelatin solution, temperature, speed and duration of whipping process, and, chitosan-gelatin ratio drastically affect the properties and the stability of the produced foams. The prepared sponges were evaluated for their morphology, drug content, and microstructure using scanning electron microscopy, mechanical properties, uptake capacity, drug release profile, and their pharmacodynamic activity in terms of the analgesic effect after implantation in Wistar rats. It was revealed that whipping 7% (w/w) gelatin solution, of pH 5.5, for 15 min at 25 degrees C with a stirring speed of 1000 rpm was the optimum conditions for stable gelatin foam generation. Moreover, homogenous, uniform chitosan-gelatin foam with small air bubbles were produced by mixing 2.5% w/w chitosan solution with 7% w/w gelatin solution in 1:5 ratio. Indeed, polyionic complexation between chitosan and gelatin overcame the drawbacks of chitosan sponge mechanical properties where, pliable, soft, and compressible sponge with high fluid uptake capacity was produced at 25 degrees C and 65% relative humidity without any added plasticizer. Drug release studies showed a successful retardation of the incorporated drug where the t50% values of the dissolution profiles were 0.55, 3.03, and 4.73 hr for cross-linked gelatin, un-cross-linked chitosan-gelatin, and cross-linked chitosan-gelatin sponges, respectively. All the release experiments followed Higuchi's diffusion mechanism over 12 hr. The achieved drug prolongation was a result of a combined effect of both cross-linking and polyelectrolyte complexation between chitosan and gelatin. The analgesic activity of the implanted tramadol hydrochloride mixed chitosan-gelatin sponge showed reasonable analgesic effect that was maintained for more than 8 hr. Therefore, the use of chitosan and gelatin together appears to allow the formulator to manipulate both the drug release profiles and the mechanical properties of the sponge that could be effectively implanted.

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Solid tumor chemotherapy using injectable gelatin microspheres containing free methotrexate and conjugated methotrexate

Cited by 18 publications

References 19 publications

Biomimetic Mineralization of Woven Bone-Like Nanocomposites: Role of Collagen Cross-Links

Biomimetic Mineralization of Woven Bone-Like Nanocomposites: Role of Collagen Cross-Links

In vivodrug release and antibacterial properties of vancomycin loaded hydroxyapatite/chitosan composite

Implantable Biodegradable Sponges: Effect of Interpolymer Complex Formation of Chitosan With Gelatin on the Release Behavior of Tramadol Hydrochloride

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