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

Abstract

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.

Biodegradable and antibacterial poly(azomethine‐urethane)‐chitosan hydrogels for potential drug delivery application

“…According to 1 H-NMR, hydroxyl ( OH), imine ( N CH), and methyl ( CH 3 ) protons of monomer were seen at 9.79, 7.66, and 1.39 ppm, respectively. In the structure of polymers, urethane ( NH), imine ( N CH), and methyl ( CH 3 ) protons were observed in the range from 9.79 to 9.80, 7.64 to 8.00, and 1.34 to 1.39 ppm, respectively.As can be seen in13 C-NMR data, hydroxyl ( C OH), imine ( N CH), and methyl ( CH 3 ) carbons of monomer were observed at 192.5, 167.5, and 30.3 ppm, respectively. Urethane ( C O), imine ( N CH), and methyl ( CH 3 ) carbons were also seen in the range from 192.2 to 192.4, 163.4 to 173.7, and 30.2 to 30.3 ppm, respectively.…”

“…Hydrogels can be obtained by using both natural polymers such as chitosan (CS), starch, or alginates, synthetic polymers such as poly(vinyl alcohol) or polyurethane, and so on. Compared with synthetic polymers, the natural polymers particularly fill the gaps that are needed in specific biomedical applications due to their good biological performance such as biodegradability, biocompatibility, abundance in nature, injectability, similarities to a cellular matrix and low‐cost production . Among the natural polymers, CS is an attractive candidate to obtain hydrogels and the properties of the prepared hydrogels such as biocompatibility, biodegradability, antibacterial effect, flexibility, and low toxicity have been significantly increased with the use of CS‐based polymer as raw material for fabricating hydrogels .…”

“…Compared with synthetic polymers, the natural polymers particularly fill the gaps that are needed in specific biomedical applications due to their good biological performance such as biodegradability, biocompatibility, abundance in nature, injectability, similarities to a cellular matrix and low-cost production. [12][13][14][15] Among the natural polymers, CS is an attractive candidate to obtain hydrogels and the properties of the prepared hydrogels such as biocompatibility, biodegradability, antibacterial effect, flexibility, and low toxicity have been significantly increased with the use of CS-based polymer as raw material for fabricating hydrogels. [16][17][18] Moreover, the use of hydrogels containing synthetic and natural polymers with well-arranged surfaces and pores has been attracted much attention for drug delivery and wound dressing applications due to their biocompatible and biodegradable in recent years.…”

Mechanical behaviour of alginate film with embedded voids under compression-decompression cycles

“…The calcium concentration in the original gel sample was found to be 4.7 wt%, whereas the calcium concentration in the exuded fluid dropped from 0.44 wt% to 0.28 wt%, even after the level of deformation was raised to 80%. This may be noted that the alginate gel releases calcium ion in exchange of sodium ion in the PBS buffer, thereby degrading the gel network within a few days 33,34 . Therefore, within the time frame of compression experiments and repeated overnight swelling, the release of calcium ion at a concentration level of 5–6% due to degradation is very much anticipated.…”

Alginate-chitosan PEC scaffolds: A useful tool for soft tissues cell therapy

“…Different ways of associating alginate and chitosan have been de scribed in the literature: by mixing at room (Florczyk et al, 2011;Xu et al, 2019;Lv et al, 2019) or higher temperature (Fletcher et al, 2017), bilayer (Banerjee and Ganguly, 2019) or layer by layer (Silva et al, 2017) assemblies, crosslinking (Baysal et al, 2016;Naghizadeha et al, 2018, Zhang et al, 2018, 3D printing (Liu et al, 2018), … They lead to biocompatible buildings whose mechanical properties can be variable (Francis et al, 2013;Salehi et al, 2019;Lv et al, 2019;Xu et al, 2019), even up to correspond to the mechanical properties of hard tissues Florczyk et al, 2013). In this context our strategy was to let these biopolymers chemically unmodified, in order to maintain their excellent initial biocompatibility, and to work on the process to obtain a macroporous 3D architecture with improved rheo logical properties compared with reference polymers.…”