Hybrid nanomaterial composed of chitosan, curcumin, ZnO and TiO2 for antibacterial therapies.

Metal nanoparticles have been tremendously utilised, such as; antibacterial and anticancer agents. Although metal nanoparticles exhibits antibacterial and anticancer activity, but the drawback of toxicity on normal cells limits their clinical applications. Therefore, improving the bioactivity of hybrid nanomaterial (HNM) and minimizing toxicity is of paramount importance for biomedical applications. Herein, a facile and simple double precipitation method was used to develop biocompatible and multifunctional HNM from antimicrobial chitosan, curcumin, ZnO and TiO2. In HNM, biomolecules chitosan and curcumin were used to control the toxicity of ZnO and TiO2 and improve their biocidal properties. The cytotxicological properties of the HNM was studied against human breast cancer (MDA-MB-231) and fibroblast (L929) cell lines. The antimicrobial activity of the HNM was examined against Escherichia coli and Staphylococcus aureus bacteria, via the well-diffusion method. In addition, the antioxidant property was evaluated by the radical scavenging method. These findings actively, support the ZTCC HNM potential, as an innovative biocidal agent for applications in the clinical and healthcare sectors.

Recent advances in green synthesized nanoparticles for bactericidal and wound healing applications.

Nanotechnology has become an exciting area of research in diverse fields, such as: healthcare, food, agriculture, cosmetics, paints, lubricants, fuel additives and other fields. This review is a novel effort to update the practioneers about the most current developments in the widespread use of green synthesized nanoparticles in medicine. Biosynthesis is widely preferred among different modes of nanoparticle synthesis since they do not require toxic chemical usage and they are environment-friendly. In the green bioprocess, plant, algal, fungal and cyanobacterial extract solutions have been utilized as nucleation/capping agents to develop effective nanomaterials for advanced medical applications. Several metal salts, such as silver, zinc, titanium and other inorganic salts, were utilized to fabricate innovative nanoparticles for healthcare applications. Irrespective of the type of wound, infection in the wound area is a widespread problem. Micro-organisms, the prime reason for wound complications, are gradually gaining resistance against the commonly used antimicrobial drugs. This necessitates the need to generate nanoparticles with efficient antimicrobial potential to keep the pathogenic microbes under control. These nanoparticles can be topically applied as an ointment and also be used by incorporating them into hydrogels, sponges or electrospun nanofibers. The main aim of this review is to highlight the recent advances in the Ag, ZnO and TiO2 nanoparticles with possible wound healing applications, coupled with the bactericidal ability of a green synthesis process.

The significance of biomacromolecule alginate for the 3D printing of hydrogels for biomedical applications.

Natural biopolymers have been widely employed as biomaterial ink hydrogels for three-dimensional (3D) extrusion bioprinting in the preparation of the next generation of bioengineering materials for healthcare applications. Alginate is a linear anionic polysaccharide with favourable properties, such as: typical rheological (gelling, viscosifying, and stabilizing dispersions) characteristics, biodegradability and biocompatibility properties. However, in order to improve alginate applicability for practical biomaterial/bio ink for advanced medical applications, it is often modified and functionalized with several polymers and nanomaterials in order to obtain better printability of alginate-based biomaterial/bio ink hydrogels. This review, principally, emphasizes the recent developments and with a comprehensive overview of alginate-based biomaterial/bio ink hydrogels and their biomaterials (3D scaffolds, tissue-like structures with hierarchical vasculatures, mimics of biological, physiological and pathological functionalities) for biomedical applications. It also addresses the significance of alginates, oxidized alginate and their functionalizations (interface) with various materials in order to improve the biomaterial/bio ink properties for 3D extrusion bioprinting applications. Finally, it provides current advances, vital roles and new perspectives of alginate-based materials and their future developments for 3D bioprinting purposes.

Biocidal and biocompatible hybrid nanomaterials from biomolecule chitosan, alginate and ZnO.

Biocidal activity and biocompatibility of nanomaterials (NMs) are crucial for healthcare applications. This study aims to develop biocidal hybrid NMs with high inhibition rates to control multidrug-resistant bacterial infection compared to conventional antibiotics. Herein, ZnO, chitosan-ZnO (CZnO) and alginate-ZnO (AZnO) NMs were synthesized via a simple one-pot technique. The one-pot process facilitates the efficiency of a chemical reaction whereby a reactant is subjected to successive chemical reactions in just one step. The resulted NMs bio-physicochemical features were analyzed using various analytical methods. The bactericidal and bacteriostatic mechanism of NMs strongly depends on the production of reactive oxygen species in NMs, due to their size, large surface areas, oxygen vacancies, ion release, and diffusion ability. The antibacterial potential of the NMs was tested against methicillin-resistant Staphylococcus aureus. The inhibition zone disclosed that the AZnO possessed an excellent antibacterial activity compared to ZnO and CZnO. Furthermore, toxicity studies revealed that the AZnO demonstrated low toxicity to the HepG2 cell lines. These results confirmed that the AZnO hybrid nanomaterials are promising futuristic biocidal agents suitable for the clinical and healthcare industries.

Biocidal chitosan-magnesium oxide nanoparticles via a green precipitation process.

In the present scenario, the development of eco-friendly multifunctional biocidal substances with low cost and high efficiency, has become the center of focus. This study is, focused on the synthesis of magnesium oxide (MgO) and chitosan-modified magnesium oxide (CMgO) nanoparticles (NPs), via a green precipitation process. In this process, leaves extract of Plumbago zeylanica L was, used as a nucleating agent. The MgO and CMgO NPs exhibit face-centered cubic structures, as confirmed by XRD studies. Morphologically, the FESEM and TEM images showed that the MgO and CMgO NPs were spherical, with an average particle size of ~40±2 and ~37±2 nm, respectively. EDX spectra were used to identify the elemental compositions of the nanoparticles. By using FTIR spectra, the Mg-O stretching frequency of MgO and CMgO NPs were observed at 431 and 435 cm-1, respectively. The photoluminescence (PL) spectra of MgO and CMgO NPs, revealed oxygen vacancies at 499 nm and 519 nm, respectively, due to the active radicals generated, which were responsible for their biocidal activities. The toxicity effects of the nanoparticles developed, on cell viability (antibacterial and anticancer), were measured on the MCF-7 cell line and six different types of gram-negative bacteria. The antibacterial activities of the nanoparticles on: Klebsiella pneumoniae, Escherichia coli, Shigella dysenteriae, Pseudomonas aeruginosa, Proteus vulgaris and Vibrio cholerae bacteria, were studied with the well diffusion method. The MgO and CMgO NPs were tested on breast cancer cell line (MCF-7) via an MTT assay and it proved that CMgO NPs possess higher anticancer properties than MgO NPs. Overall, CMgO NPs showed a higher amount of cytotoxicity for both the bacterial and cancer cells when compared to the MgO NPs. Toxicity studies of fibroblast L929 cells revealed that the CMgO NPs were less harmful to the healthy cells when compared to the MgO NPs. These results suggest that biopolymer chitosan-modified MgO NPs can be used for healthcare industrial applications in order to improve human health conditions.

Biocidal (bacterial and cancer cells) activities of chitosan/CuO nanomaterial, synthesized via a green process.

Biopolymer-based nanomaterials have been developed as antimicrobial and anticancer agents due to their advanced physical, chemical and biomedical characteristics. Herein, chitosan-copper oxide nanomaterial was, successfully synthesized by a green method. In this process, copper salt was nucleated with Psidium guajava leaves extract in order to form the nanomaterial in the chitosan network. Attenuated total reflection-fourier transform, infrared spectroscopy, X-ray diffraction, Dynamic light scattering, Transmission electron microscope, Field emission scanning electron microscopy/Energy dispersive X-ray analysis, X-ray photoelectron spectroscopy and Photoluminescence spectroscopy techniques were, employed to characterize the synthesized nanomaterial. The average size of the nanomaterial was identified to be ∼52.49 nm with XRD. The antibacterial study of CCuO NM showed higher activity than the commercial amoxicillin against gram-positive (G + ve) (Staphylococcus aureus, Bacillus subtilis) and gram-negative (G-ve) bacteria (Klebsiella pneumonia, Escherichia coli). CCuO NM showed in-vitro anticancer potential against human cervical cancer cells (Hela) with an IC50 concentration of 34.69 µg/mL. Photoluminescence spectrum of CCuO NM showed a green emission (oxygen vacancies) observed at ∼516 nm, which is attributed to the generation of reactive oxygen species (ROS) by the nanomaterial, which is believed, to be responsible for the biocidal (cell death) effects. These results suggested that CCuO is a promising nanomaterial that could be suitable for advanced applications in the healthcare industries.

Biocidal activity of Ba2+-doped CeO2 NPs against Streptococcus mutans and Staphylococcus aureus bacterial strains.

Mishandling of antibiotics often leads to the development of multiple drug resistance (MDR) among microbes, resulting in the failure of infection treatments and putting human health at great risk. As a response, unique nanomaterials with superior bioactivity must be developed to combat bacterial infections. Herein, CeO2-based nanomaterials (NMs) were synthesized by employing cerium(iii) nitrate and selective alkaline ions. Moreover, the influence of alkaline ions on CeO2 was investigated, and their characteristics, viz.: biochemical, structural, and optical properties, were altered. The size of nano Ba-doped CeO2 (BCO) was ∼2.3 nm, relatively smaller than other NMs and the antibacterial potential of CeO2, Mg-doped CeO2 (MCO), Ca-doped CeO2 (CCO), Sr-doped CeO2 (SCO), and Ba-doped CeO2 (BCO) NMs against Streptococcus mutans (S. mutans) and Staphylococcus aureus (S. aureus) strains was assessed. BCO outperformed all NMs in terms of antibacterial efficacy. In addition, achieving the enhanced bioactivity of BCO due to reduced particle size facilitated the easy penetration into the bacterial membrane and the presence of a sizeable interfacial surface. In this study, the minimum quantity of BCO required to achieve the complete inhibition of bacteria was determined to be 1000 µg mL-1 and 1500 µg mL-1 for S. mutans and S. aureus, respectively. The cytotoxicity test with L929 fibroblast cells demonstrated that BCO was less toxic to healthy cells. Furthermore, BCO did not show any toxicity and cell morphological changes in the L929 fibroblast cells, which is similar to the control cell morphology. Overall, the results suggest that nano BCO can be used in biomedical applications, which can potentially help improve human health conditions.

Hydroxypropyl methylcellulose-copper nanoparticle and its nanocomposite hydrogel films for antibacterial application.

Currently, special emphasis is being given to the design and fabrication of antibacterial nanocomposite hydrogels for wound dressing applications. Herein, we report the synthesis and characterization of hydroxypropyl methylcellulose (HPMC) reinforced with HPMC capped copper nanoparticles (HCu NPs) based nanocomposite hydrogel films (NHFs). Spherical nanostructures of HCu NPs (∼40 nm) were achieved by facile precipitation technique using ascorbic acid as a nucleating agent and subsequently made their NHFs via solution casting method. Spectral, thermal and structural characteristics of the developed materials were carried out. Antibacterial activity of the resultant NHFs showed the MIC and MBC values of 350 and 1400 µg/mL for S. aureus, and 500 and 2000 µg/mL for E. coli, respectively. These results conveyed that the HCu NPs incorporated HPMC NHFs can be used effectively in antibacterial applications.

An ecofriendly nanocomposite of bacterial cellulose and hydroxyapatite efficiently removes lead from water.

An environmentally friendly nanocomposite adsorbent composed of two renewable biomaterials, bacterial cellulose (BC) nanofibrils and hydroxyapatite (HA) nanocrystals, was synthetized by an in situ wet chemical precipitation technique, using clam shell biowaste as feedstock. HA nanocrystals embedded in an ultrafine BC network were confirmed and characterized trough different instrumental techniques (SEM, FTIR, XRD, EDS, surface charge and BET analysis), describing its nanostructure, chemical composition and thermal stability. The adsorptive removal of lead ions by the nanocomposite was investigated through batch experiments conducted under different pH, contact times and Pb(II) initial concentrations, proving that the process was highly favorable according to the Langmuir isotherm model (monolayer adsorption) with chemisorption as the main mechanism and kinetic data obeying a nonlinear pseudo-second order kinetic model. The developed nanocomposite showed a strong removal capacity of Pb(II) both in batch experiments (192 mg/g) and packed-bed column systems (188 mg/g), placing this new nanocomposite among top-performing BC-based biomaterials for lead removal.

Biomolecule chitosan, curcumin and ZnO-based antibacterial nanomaterial, via a one-pot process.

As a result of the existence of drug-resistant bacteria and the attendant deficiency of innovative antibiotics, the therapeutic and the clinical sectors are, continually, in search of appropriate multifunctional nanomedicines. Herein, curcumin-chitosan-zinc oxide (CCZ) was successfully synthesized by a one-pot method. Transmission electron micrograph reveals that curcumin and chitosan were layered on a hexagonal ZnO and the particles are sized to ∼48 ±2nm. X-ray diffractogram confirmed the formation of CCZ crystal structure. The photoluminescence spectra of CCZ, shows blue and green emissions at 499 nm and 519 nm, respectively, due to the active radicals generated in the nanomaterial, which are responsible for the associated antimicrobial and anticancer activities. The antibacterial activity of the CCZ, performed against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli), showed a greater antibacterial effect than the commercial amoxicillin. The cytotoxic effect of the CCZ nanomaterial was examined in cultured (MCF-7) human breast cancer cells. An IC50 concentration value of 43.53 µg/mL, was recorded when evaluated after 24 h of CCZ with the MCF-7 cell line. From this study, it is believed that CCZ is a highly promising nanomaterial, which will be suitable for advanced clinical applications.

Carboxymethyl cellulose-based materials for infection control and wound healing: A review.

The development of ideal wound dressing materials with excellent characteristics is currently a major demand in wound therapy. In recent years, carboxymethyl cellulose (CMC)-based wound dressing materials have been of immense attraction due to their noble properties, such as: biocompatibility, biodegradability, tissue resembling, low cost and non-toxic. It is used extensively, in a variety of applications in the biomedical and pharmaceutical fields. The hydrophilic nature of CMC, makes it possible to blend and cross-link with other materials, such as: synthetic polymers, natural polymers and inorganic materials and it enables the preparation of innovative wound dressing biomaterials. Hence, this review, focuses on the intrinsic characteristics of CMC-based wound dressing materials, including hydrogels, films, 3D printing, fibres, gauzes and their recent advancements in chronic wound healing.

Alginate-based composite materials for wound dressing application:A mini review.

Alginate biopolymer has been used in the design and development of several wound dressing materials in order to improve the efficiency of wound healing. Mainly, alginate improves the hydrophilic nature of wound dressing materials in order to create the required moist wound environment, remove wound exudate and increase the speed of skin recovery of the wound. In addition, alginate can easily cross-link with other organic and inorganic materials and they can promote wound healing in clinical applications. This review article addresses the importance of alginates and the roles of derivative polymeric materials in wound dressing biomaterials. Additionally, studies on recent alginate-based wound dressing materials are discussed.

Biosynthesis of CMC-Guar gum-Ag0 nanocomposites for inactivation of food pathogenic microbes and its effect on the shelf life of strawberries.

A few fruits have short post-harvest life due to high metabolic activity, relatively high water content vulnerability towards microbes and loss of weight during their storage. Carboxymethyl cellulose (CMC)-Guar gum-silver nanocomposite films (CG-Ag0NC) are developed to address these issues. The silver nanoparticles were generated in the CMC-Guar gum matrix through a reduction by Mentha leaves extract. All the films were characterized by UV-vis spectroscopy, FT-IR, TGA, XRD, SEM, TEM, and zeta potential measurements. The antimicrobial activity of CG and CG-Ag0NC was measured by determining their zone inhibition values with ten food pathogenic microbes. The shelf life of CG-Ag0NC films was tested with the model fruit, strawberries, and compared with other packing films. The results are encouraging in terms of freshness, shelf-life and weight loss.

Chitosan-pluronic based Cu nanocomposite hydrogels for prototype antimicrobial applications.

Copper nanoparticles were synthesized via precipitation technique using the pseudonatural cationic chitosan biopolymer as a stabilizing agent. The nanoparticles developed were successfully incorporated into the 1:1 ratio of blended chitosan: pluronic F127 polymer solution and made their nanocomposite hydrogels by solution casting method. The formed copper-based nanocomposite hydrogels were characterized by using Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy and transmission electron microscopy studies. The antimicrobial activity of the fabricated nanocomposite hydrogels was tested via an inhibition zone process against both E. coli (gram-negative) and S. aureus (gram-positive) bacteria. The results conveyed that the copper-embedded chitosan-pluronic\ F127 nanocomposite hydrogels can be used effectively for antimicrobial applications as well as for wound care applications.

Generation of engineered core-shell antibiotic nanoparticles.

Well-defined nanocomposite structures have received significant attention due to their superior combinatorial properties. Rational tuning of the core and shell of the nanostructure(s) can offer potent antibacterial activity. Such advanced core-shell nanocomposite methodologies allow not only the incorporation of antibacterial agents on the shell but also provide its stability and nurture antibacterial activity. Herein, antibiotic zinc oxide-curcumin (ZnO-Cum) core-shell nanoparticles for antibacterial application were synthesised. The ZnO-Cum core-shell nanoparticles were prepared by curcumin nanolayer deposition on zinc oxide nanoparticles via a sonication process. The resulting ZnO-Cum core-shell nanoparticles were spiracle in shape with a ∼45 nm ZnO core and ∼12 nm curcumin shell layer size, respectively, determined by transmission electron microscopy. X-ray diffraction analysis confirmed the formation of a core-shell crystal structure. Additionally, UV-DRS and ATR-FTIR spectral analysis support the existence of ZnO and curcumin in a core-shell nanocomposite. The antibacterial activities of nanoparticles developed were studied against Staphylococcus aureus and Streptococcus pneumoniae and Escherichia coli and Shigella dysenteriae bacterial stains using the diffusion method. A greater inhibition of the growth of Gram positive and negative bacteria was noticed upon treatment with core-shell ZnO and curcumin nanoparticles than the commercial antibiotic amoxicillin which indicates their antibacterial property. The findings of this study provide evidence that the zinc oxide-curcumin core-shell nanoparticles may be highly promising for antibacterial and biomedical applications.

Chitosan capped copper oxide/copper nanoparticles encapsulated microbial resistant nanocomposite films.

Chitosan (CH) capped inorganic nanomaterials have been considered as significant antibacterial materials in the clinical field. This work shows the synthesis of two new different antibacterial composite films as a result of the incorporation of CH capped copper oxide (CHCuO) and copper (CHCu) nanoparticles (NPs). Here, CHCuO and CHCu NPs were achieved by a facile chemical reduction of Cu2+ ions using sodium hydroxide and ascorbic acid. TEM analysis revealed the morphology as rod-type nanoflakes for CHCuO and a spherical shape for CHCu NPs with ~7 ±â€¯2 nm size. Antimicrobial activity of the developed materials was studied by the inhibition zone method, against both gram-negative and gram-positive bacteria. The antimicrobial activity revealed that the CHCuO NPs and CHCuO-CH film showed a higher inhibition zone than the other nanomaterials. The results suggested that the synthesized materials can be used in wound dressing applications.

Heavy metal removal from aqueous systems using hydroxyapatite nanocrystals derived from clam shells.

Hydroxyapatite (HA) was synthesized by wet chemical precipitation, using clam shell (CS) waste as feedstock. SEM and TEM observation of the produced hydroxyapatite revealed the presence of rod-shaped nanocrystals, while XRD and EDS analyses confirmed the characteristic patterns of hydroxyapatite molecules. This material was subsequently employed as a sorbent for heavy metal removal from aqueous solutions, both in batch and column equilibrium procedures. In batch studies, higher sorption efficiencies were obtained at pH 5, with the highest adsorption capacities of 265, 64, and 55 mg g-1 for Pb(ii), Cd(ii), and Cu(ii), respectively. In addition, an adsorption capacity of 42.5 mg g-1 was determined using a CS-HA packed bed column fed with a solution of Pb(ii). Finally, the breakthrough curve was fitted with Thomas model in order to predict column behavior and scaling up.

Nano-hydroxyapatite polymeric hydrogels for dye removal.

Herein, two kinds of nano-hydroxyapatite were synthesized from Clam and Magellan shell by wet chemical precipitation method. Mainly, carboxymethyl cellulose/acrylamide/nano-hydroxyapatite composite hydrogels were developed via a free-radical polymerization process and investigated as a sorbent for Acid Blue 113 (AB) from aqueous AB solution. The swelled and kinetic behaviours of hydrogels were investigated using a gravimetric method. The swelling properties of the CMC-AM-hydrogels were influenced by the calcium electrolytes (Ca2+) content in nano-hydroxyapatites. The diffusion coefficient value increased with the increase of nano-hydroxyapatite content in the CMC-AM/nHA-CS (0.22353-0.27681 cm2 s-1) and CMC-AM/nHA-MS (0.22377-0.29737 cm2 s-1) hydrogels. The mechanism of water diffusion was found to be anomalous transport. The CMC-AM/nHA-MS hydrogels showed high AB absorption efficiency and adsorption capacities. These results explained that the nano-hydroxyapatites of Magellan shells based hydrogels are attractive nanocomposite hydrogels for the adsorption of dye in the water purification applications.

A mini review on hydrogels classification and recent developments in miscellaneous applications.

Hydrogels are composed of three-dimensional smart and/or hungry networks, which do not dissolve in water but swell considerably in an aqueous medium, demonstrating an extraordinary ability to absorb water into the reticulated structure. Such inherent feature is a subject of considerable scientific research interest which leads to a dominating path in extending their potential in hi-tech applications. Over the past decades, significant progress has been made in the field of hydrogels. Further, explorations are continuously being made in all directions at an accelerated pace for their extensive usage. In view of this, the present review discusses the subject on the miscellaneous hydrogels with regard to their raw materials, methods of fabrication and applications. In addition, this article summarizes the classification of hydrogels, based on their cross-linking and physical states. Lately, a brief outlook on the future prospects of hydrogels is also presented.

Calcinated tea and cellulose composite films and its dielectric and lead adsorption properties.

In this paper, calcinated tea and cellulose composite (CTCC) films were fabricated via solution casting method. Chemical structure, morphology, crystallinity and thermal stability of the fabricated films were characterized by using Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction and thermogravimetric analysis. The effect of calcinated tea loading on the properties of the prepared CTCC films was studied. The results suggest that the prepared CTCC films show higher mechanical properties, thermal stability and dielectric constant than the neat cellulose film. In addition, the CTCC films adsorb Pb2+ ions and its adsorption performance depends on the calcinated tea content and pH level. The CTCC films are useful for sensors, flexible capacitor as well as lead adsorption applications.