Controlled production of alginate nanocomposites with incorporated silver nanoparticles aimed for biomedical applications

Abstract

Production of nanocomposite alginate microbeads with electrochemically synthesized silver nanoparticles (AgNPs) based on electrostatic extrusion technique was investigated with respect to potentials for utilization in pharmaceutical and biomedical applications. It was shown that electrochemical synthesis of AgNPs results in reduction of practically all Ag+ ions present in the initial solution yielding stable Ag/alginate colloid solutions that were demonstrated to be suitable for sterilization, manipulation, and electrostatic extrusion with retention of AgNPs. Presence of AgNPs in alginate colloid solutions had negligible effects on the size of the produced Ag/alginate microbeads, which was chiefly determined by the applied electrostatic potential during the extrusion. On the other hand, incorporation of AgNPs within the alginate hydrogel induced slight changes in biomechanical properties determined in a biomimetic bioreactor, so that packed beds of nanocomposite Ag/alginate microbeads exhibited slightly higher dynamic compression modulus as compared to that of control alginate microbeads (154 ± 4 and 141 ± 2 kPa, respectively). On the other hand, equilibrium unconfined compression modulus was significantly lower for nanocomposite microbeads as compared to that of controls (34 ± 2 and 47 ± 0.5 kPa, respectively). [Projekat Ministarstva nauke Republike Srbije, br. III 45019 i br. Eureka E!6749

Functional bioreactor characterization to assess potentials of nanocomposites based on different alginate types and silver nanoparticles for use as cartilage tissue implants

“…This finding can be explained by alginate gel contraction during 48 h of gelling as reported previously. 26,40,41 It should be noted that the absorbance maximum increase and corresponding gel contraction were significantly higher in the case of HG alginate as compared to the LG alginate (~2.5-vs.~1.4-fold increase, respectively, Fig. 1).…”

“…In all experiments, dynamic uniaxial unconfined compression was performed in the regime 1 h on/1 h off, at the loading rate of 337.5 μm/s, 0.84 Hz frequency, and 0.2 mm total displacement corresponding to ~10% strain of the Ag/alginate disc. The compression parameters were selected based on cartilage tissue engineering studies reported in literature (e.g., ) and our previous studies of alginate based hydrogels …”

“…The compression parameters were selected based on cartilage tissue engineering studies reported in literature (e.g., [29][30][31][32] and our previous studies of alginate based hydrogels. 14,26,33,34 Stability of Ag/alginate discs under bioreactor conditions Both HG and LG discs (n = 3) were evaluated regarding stability and mechanical properties in the culture medium in the bioreactor for up to 7 days. Outputs from the bioreactor load sensor were acquired daily and applied stresses were calculated by using the plunger area as described previously.…”

Comparative in vivo evaluation of novel formulations based on alginate and silver nanoparticles for wound treatments

“…[38][39][40] This method is particularly advantageous for potential applications in biomedicine and pharmacy due to the precise control of particle size and the use of only sodium alginate and silver precursors -AgNO 3 and KNO 3 , without chemical reducing agents because the silver ions are reduced to AgNPs by electrical current. Ag/alginate colloid solutions could be further crosslinked to form nanocomposite hydrogels in different forms such as films, sheets, microbeads 38,39,41 and microfibers. 42 In addition, the obtained nanocomposite hydrogels could be dried at room temperature with preservation of AgNPs.…”

Biodegradable sodium alginate‐based semi‐interpenetrating polymer network hydrogels for antibacterial application

“…Recently, sodium alginate‐based silver nanocomposites have been reported for catalytic and antibacterial applications . NPs are incorporated into hydrogel matrix by simply mixing the NPs with the preformed hydrogel or by adding the NPs during the gelation process where the NPs could be entrapped during the swelling of the material.…”