Synthesis and Characterization of Biomimetic Hydroxy Apatite-Silver Impregnated Soy Protein Isolate Nanocomposites for Dental Implantations

Abstract

A novel class of biomimetic hydroxyapatite (HAP), poly(vinyl alcohol) (PVA) and silver nanoparticles (AgNPs) impregnated soy protein isolate (SPI)-ternary and quaternary nanocomposites were fabricated by an environmentally benign hydrothermal precipitation process under UV irradiation. Various physico-chemical and mechanical characteristics showed improved mechanical properties that open up newer vistas in biomedical applications, especially for dental implantations and repairs. The SEM, FT-IR, powder-XRD, particle size distribution analysis, TG-DTA, and DSC results confirmed the complete miscibility of soy protein isolate, hydroxyapatite and poly(vinyl alcohol) through one another by strong hydrogen bonding and silver nanoparticles were evenly distributed into nano-matrix and are stable without any aggregation. The mechanical properties (tensile strength), water absorption test and in vitro antibacterial studies confirmed that soy protein isolate based composites have enough mechanical stability, low water absorption and low bacterial adhesion. The incorporation of poly(vinyl alcohol) as neutral fillers boosts the tensile strength. The TG-DTA and DSC studies envisaged better miscibility and morphological changes of hydroxyapatite, poly(vinyl alcohol) and silver nanoparticles impregnated soy protein isolate with one another with an induced thermal stability. This novel class of SPI/HAP/PVA/Ag nanocomposites shall be a potential alternative class of materials for teeth and bone, orthopaedic dental implant due to their chemical and biological similarity to human hard tissues.

Applications of Silver Nanoparticles in Dentistry: Advances and Technological Innovation

“…The differentiation between chemical processes is represented by the reduction agents and stabilizers used, such as sodium citrate, ascorbate, sodium borohydride (NaBH 4 ), elemental hydrogen, polyol process, Tollens reagent, n , n -dimethylformamide (DMF), and poly (ethylene glycol)-block copolymers. Several protective agents (stabilizers) have been used, such as thiols, amines, acids, alcohols [ 93 ], and polymeric compounds such as chitosan [ 25 , 26 , 56 ] and polymethylmethacrylate [ 27 , 51 , 53 , 68 , 92 ]. These agents stabilize dispersive NPs during their synthesis and protect NPs that can be absorbed on, or bind onto, nanoparticle surfaces, avoiding their agglomeration and sedimentation [ 94 ].…”

“…Studies have also revealed that AgNP exerts antibacterial activity against Streptococcus mutans [ 3 , 42 , 49 , 60 , 69 ], Staphylococcus aureus [ 3 , 54 , 58 , 69 , 74 , 93 ], Streptococcus sobrinus , Lactobacillus acidophilus , Lactobacillus casei [ 42 ], Streptococcus sanguinis [ 49 ], Enterococcus faecalis [ 69 , 93 ], and Actinomyces actinomycetemcomitans [ 49 ]. AgNPs also prevent the formation of E. faecalis , S. aureus , Streptococcus gordonii , Streptococcus mitis , and Streptococcus mutans biofilms [ 30 ].…”

“…Despite their thick, protective outer peptidoglycan layer, Gram-positive bacteria are very vulnerable to the antimicrobial action of silver [ 30 ]. Gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa exhibit no resistance to the antimicrobial action of silver [ 30 , 54 , 58 , 74 , 93 ].…”

Status of Plant Protein-Based Green Scaffolds for Regenerative Medicine Applications

“…In another study, silver nanoparticles were synthesized into SPI/HAP/PVA composites by a green method using UV radiation. The synthesized nanocomposites exhibited enhanced antibacterial activity against five different bacterial strains; the authors claimed that it could be a potential candidate for orthodontic applications [140]. Qu et al demonstrated that incorporating highly dispersible TiO 2 nanoparticles is an effective approach for enhancing the mechanical, thermal, and antimicrobial properties of zein/chitosan films.…”

To investigate interfacial interaction between soy protein isolate biocomposite thin films reinforced with poly (vinyl alcohol) matrix

“…[ 31 ] Therefore, various nanofillers are introduced into SPI/PVA materials. [ 32 ]…”