Diffusion in and around alginate and chitosan films with embedded sub-millimeter voids

Patra, Sanjib K.; Bal, Dharmendra Kumar; Ganguly, Suvankar

doi:10.1016/j.msec.2015.09.079

Cited by 9 publications

(7 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the contrary, the release of vitamin B 12 from alginate occurred within an hour. Even though the solutes were considered different in the two polymer gel substrates, our experience with these two gels suggests that diffusivity of solute is significantly lower in crosslinked chitosan, than in calcium alginate . Figure further shows that the composite films released the solute at a much slower rate.…”

Section: Resultsmentioning

confidence: 97%

Alginate–chitosan composite hydrogel film with macrovoids in the inner layer for biomedical applications

Banerjee

Ganguly

2019

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

Making of a layered composite using two biopolymer gels with regularly aligned voids in the inner layer is described in this article. Calcium alginate constituted the inner layer, within which voids of 500 μm diameter were embedded in monolayer or in multiple layers using a fluidic device for bubbling. The chitosan without any additional crosslinker was used to form the outer layer. The layered structure enabled compartmentalization of drug hold‐up, and differential release rates. These aspects were reviewed using bovine serum albumin and vitamin B12 as model solutes. The presence of voids at the inner layer of alginate increased the uptake, raising the level of absorptivity to more than 4000%. The composite film could hold two solutes at a time. The one, held inside the alginate layer started releasing only after 1 h of dipping in the release media. The adhesive strength between layers and the response of the composite film to compressive deformation are studied here. The effect of single or multiple layers of voids in the inner layer is reviewed. The slowing of degradation rate due to chitosan‐encapsulation is experimentally determined. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47599.

show abstract

Section: Resultsmentioning

confidence: 97%

Alginate–chitosan composite hydrogel film with macrovoids in the inner layer for biomedical applications

Banerjee

Ganguly

2019

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

show abstract

“…Then, diffusional resistance inside the microspheres is negligible compared to the liquid boundary layer resistance i.e. the rate-limiting step, being able to describe the simplified release process by means of the mass transfer coefficient, h [41, 42]. However, based on the experimental in vitro profiles mentioned above, a distributed system must be assumed, where the concentration gradient inside the microspheres is rate limiting.…”

Section: Resultsmentioning

confidence: 99%

New injectable two-step forming hydrogel for delivery of bioactive substances in tissue regeneration

Pérez-Herrero

García-García

Gómez‐Morales

et al. 2019

Regenerative Biomaterials

View full text Add to dashboard Cite

A hydrogel based on chitosan, collagen, hydroxypropyl-γ-cyclodextrin and polyethylene glycol was developed and characterized. The incorporation of nano-hydroxyapatite and pre-encapsulated hydrophobic/hydrophilic model drugs diminished the porosity of hydrogel from 81.62 ± 2.25% to 69.98 ± 3.07%. Interactions between components of hydrogel, demonstrated by FTIR spectroscopy and rheology, generated a network that was able to trap bioactive components and delay the burst delivery. The thixotropic behavior of hydrogel provided adaptability to facilitate its implantation in a minimally invasive way. Release profiles from microspheres included or not in hydrogel revealed a two-phase behavior with a burst- and a controlled-release period. The same release rate for microspheres included or not in the hydrogel in the controlled-release period demonstrated that mass transfer process was controlled by internal diffusion. Effective diffusion coefficients, D eff , that describe internal diffusion inside microspheres, and mass transfer coefficients, h , i.e. the contribution of hydrogel to mass transfer, were determined using ‘genetic algorithms’, obtaining values between 2.64·10 −15 and 6.67·10 −15 m 2 /s for D eff and 8.50·10 −10 to 3.04·10 −9 m/s for h . The proposed model fits experimental data, obtaining an R 2 -value ranged between 95.41 and 98.87%. In vitro culture of mesenchymal stem cells in hydrogel showed no manifestations of intolerance or toxicity, observing an intense proliferation of the cells after 7 days, being most of the scaffold surface occupied by living cells.

show abstract

“…The bubble formation process was carefully observed under a microscope. The orifice in throat device used in this study is a modified form of co‐flow arrangement. Here, a squeeze at the tip of outer capillary forces the bubble to deform further, and disintegrate into smaller bubbles.…”

Section: Resultsmentioning

confidence: 99%

“…The bubbles were introduced by co‐flowing the aqueous phase and the nitrogen gas in the orifice in throat device . A syringe pump from Harvard Apparatus, U.S.A, and a mass flow controller from Alicat Scientific, U.S.A were used to inject the aqueous and gas phases respectively at precise rates.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Alginate‐gelatin blend with embedded voids for controlled release applications

Banerjee

Patra

Ganguly

2017

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

Alginate gel is known for its potential use in the controlled release of drugs, and as a 3-D structure for tissue harvesting. In this paper, the tuning of the performance of alginate gel by blending gelatin in the aqueous phase, and introducing bubbles in a regular alignment are discussed. Monodisperse bubbles in millimetre or submillimeter size were introduced into the aqueous suspension of the blend prior to gelation, using a novel fluidic arrangement. The CaCl 2 solution, added as the crosslinker diffused into the lamella, forming a rigid structure of calcium alginate. The effective blending of gelatin in alginate provided benefits of both the biopolymers in the final product. The benefits are the excellent absorption capacity of alginate and the mechanical strength of gelatin in the blend. The selfaligned voids enabled further tuning of absorption capacity and/or rate of release. Also, the presence of voids enhanced the elastomeric quality of the composite structure. The uptake of Vitamin B 12 solution was measured gravimetrically, and the release in PBS buffer on a shaker was studied using UV-vis spectrophotometer. For different loadings of void and gelatin, the absorption capacity, mechanical strength and the compression behavior were analysed.

show abstract

Diffusion in and around alginate and chitosan films with embedded sub-millimeter voids

Cited by 9 publications

References 34 publications

Alginate–chitosan composite hydrogel film with macrovoids in the inner layer for biomedical applications

Alginate–chitosan composite hydrogel film with macrovoids in the inner layer for biomedical applications

New injectable two-step forming hydrogel for delivery of bioactive substances in tissue regeneration

Alginate‐gelatin blend with embedded voids for controlled release applications

Contact Info

Product

Resources

About