Facile preparation of antibacterial chitosan/graphene oxide-Ag bio-nanocomposite hydrogel beads for controlled release of doxorubicin

Trends in sustainable chitosan-based hydrogel technology for circular biomedical engineering: A review

Eco-friendly materials have emerged in biomedical engineering, driving major advances in chitosan-based hydrogels. These hydrogels offer a promising green alternative to conventional polymers due to their non-toxicity, biodegradability, biocompatibility, environmental friendliness, affordability, and easy accessibility. Known for their remarkable properties such as drug encapsulation, delivery capabilities, biosensing, functional scaffolding, and antimicrobial behavior, chitosan hydrogels are at the forefront of biomedical research. This paper explores the fabrication and modification methods of chitosan hydrogels for diverse applications, highlighting their role in advancing climate-neutral healthcare technologies. It reviews significant scientific advancements and trends chitosan hydrogels focusing on cancer diagnosis, drug delivery, and wound care. Additionally, it addresses current challenges and green synthesis practices that support a circular economy, enhancing biomedical sustainability. By providing an in-depth analysis of the latest evidence on climate-neutral management, this review aims to facilitate informed decision-making and foster the development of sustainable strategies leveraging chitosan hydrogel technology. The insights from this comprehensive examination are pivotal for steering future research and applications in sustainable biomedical solutions.

Recent Advancements in Metallic Au- and Ag-Based Chitosan Nanocomposite Derivatives for Enhanced Anticancer Drug Delivery

The rapid advancements in nanotechnology in the field of nanomedicine have the potential to significantly enhance therapeutic strategies for cancer treatment. There is considerable promise for enhancing the efficacy of cancer therapy through the manufacture of innovative nanocomposite materials. Metallic nanoparticles have been found to enhance the release of anticancer medications that are loaded onto them, resulting in a sustained release, hence reducing the dosage required for drug administration and preventing their buildup in healthy cells. The combination of nanotechnology with biocompatible materials offers new prospects for the development of advanced therapies that exhibit enhanced selectivity, reduced adverse effects, and improved patient outcomes. Chitosan (CS), a polysaccharide possessing distinct physicochemical properties, exhibits favorable attributes for controlled drug delivery due to its biocompatibility and biodegradability. Chitosan nanocomposites exhibit heightened stability, improved biocompatibility, and prolonged release characteristics for anticancer medicines. The incorporation of gold (Au) nanoparticles into the chitosan nanocomposite results in the manifestation of photothermal characteristics, whereas the inclusion of silver (Ag) nanoparticles boosts the antibacterial capabilities of the synthesized nanocomposite. The objective of this review is to investigate the recent progress in the utilization of Ag and Au nanoparticles, or a combination thereof, within a chitosan matrix or its modified derivatives for the purpose of anticancer drug delivery. The research findings for the potential of a chitosan nanocomposite to deliver various anticancer drugs, such as doxorubicin, 5-Fluroacil, curcumin, paclitaxel, and 6-mercaptopurine, were investigated. Moreover, various modifications carried out on the chitosan matrix phase and the nanocomposite surfaces to enhance targeting selectivity, loading efficiency, and pH sensitivity were highlighted. In addition, challenges and perspectives that could motivate further research related to the applications of chitosan nanocomposites in cancer therapy were summarized.

Nanoparticles incorporated hydrogels for delivery of antimicrobial agents: developments and trends

The prevention and treatment of microbial infections is an imminent global public health concern due to the poor antimicrobial performance of the existing antimicrobial regime and rapidly emerging antibiotic resistance in pathogenic microbes. In order to overcome these problems and effectively control bacterial infections, various new treatment modalities have been identified. To attempt this, various micro- and macro-molecular antimicrobial agents that function by microbial membrane disruption have been developed with improved antimicrobial activity and lesser resistance. Antimicrobial nanoparticle-hydrogels systems comprising antimicrobial agents (antibiotics, biological extracts, and antimicrobial peptides) loaded nanoparticles or antimicrobial nanoparticles (metal or metal oxide) constitute an important class of biomaterials for the prevention and treatment of infections. Hydrogels that incorporate nanoparticles can offer an effective strategy for delivering antimicrobial agents (or nanoparticles) in a controlled, sustained, and targeted manner. In this review, we have described an overview of recent advancements in nanoparticle-hydrogel hybrid systems for antimicrobial agent delivery. Firstly, we have provided an overview of the nanoparticle hydrogel system and discussed various advantages of these systems in biomedical and pharmaceutical applications. Thereafter, different hybrid hydrogel systems encapsulating antibacterial metal/metal oxide nanoparticles, polymeric nanoparticles, antibiotics, biological extracts, and antimicrobial peptides for controlling infections have been reviewed in detail. Finally, the challenges and future prospects of nanoparticle-hydrogel systems have been discussed.

Nanocomposite of starch, gelatin and itaconic acid-based biodegradable hydrogel and ZnO/cellulose nanofiber: A pH-sensitive sustained drug delivery vehicle

In recent years, hydrogels as drug carriers have been receiving great interest due to their ability to change their behavior in response to one or more external stimuli. However, their initial burst release profile limits their practical applications. Therefore, we prepared a bio-based hydrogel nanocomposite (HNC) using starch, itaconic acid, acrylic acid and gelatin in the presence of CNF/ZnO-based nanohybrid (ZONH) and used it to evaluate the pH-sensitive drug release properties in different pH solutions. The prepared HNCs were analyzed using various spectroscopic and microscopic techniques. The BET analysis and swelling test of the HNC indicated improved porosity and swelling capacity due to the addition of ZONH. From the drug release study, sustained drug release rate was observed at pH 4 than those at pH 7.4 and 9, indicating controlled release as well as pH responsive behavior of the HNC. Moreover, the drug released HNC was reused as a photocatalyst for dye degradation and achieved good degradation (%). The antibacterial activity of ZONH and HNC was observed against EC and SA bacterial strains from the antibacterial test. In summary, the prepared HNC can be considered as a potential sustainable DDS for biomedical applications as well as a photocatalyst for dye contaminated water treatment.

Exploration of inorganic nanoparticles for revolutionary drug delivery applications: a critical review

The nanosystems for delivering drugs which have evolved with time, are being designed for greater drug efficiency and lesser side-effects, and are also complemented by the advancement of numerous innovative materials. In comparison to the organic nanoparticles, the inorganic nanoparticles are stable, have a wide range of physicochemical, mechanical, magnetic, and optical characteristics, and also have the capability to get modified using some ligands to enrich their attraction towards the molecules at the target site, which makes them appealing for bio-imaging and drug delivery applications. One of the strong benefits of using the inorganic nanoparticles-drug conjugate is the possibility of delivering the drugs to the affected cells locally, thus reducing the side-effects like cytotoxicity, and facilitating a higher efficacy of the therapeutic drug. This review features the direct and indirect effects of such inorganic nanoparticles like gold, silver, graphene-based, hydroxyapatite, iron oxide, ZnO, and CeO2 nanoparticles in developing effective drug carrier systems. This article has remarked the peculiarities of these nanoparticle-based systems in pulmonary, ocular, wound healing, and antibacterial drug deliveries as well as in delivering drugs across Blood-Brain-Barrier (BBB) and acting as agents for cancer theranostics. Additionally, the article sheds light on the plausible modifications that can be carried out on the inorganic nanoparticles, from a researcher's perspective, which could open a new pathway.

Ag nanocomposite hydrogels with immune and regenerative microenvironment regulation promote scarless healing of infected wounds

BACKGROUND

Bacterial infection, complex wound microenvironment and persistent inflammation cause delayed wound healing and scar formation, thereby disrupting the normal function and appearance of skin tissue, which is one of the most problematic clinical issues. Although Ag NPs have a strong antibacterial effect, they tend to oxidize and form aggregates in aqueous solution, which reduces their antibacterial efficacy and increases their toxicity to tissues and organs. Current research on scar treatment is limited and mainly relies on growth factors and drugs to reduce inflammation and scar tissue formation. Therefore, there is a need to develop methods that effectively combine drug delivery, antimicrobial and anti-inflammatory agents to modulate the wound microenvironment, promote wound healing, and prevent skin scarring.

RESULTS

Herein, we developed an innovative Ag nanocomposite hydrogel (Ag NCH) by incorporating Ag nanoparticles (Ag NPs) into a matrix formed by linking catechol-modified hyaluronic acid (HA-CA) with 4-arm PEG-SH. The Ag NPs serve dual functions: they act as reservoirs for releasing Ag/Ag+ at the wound site to combat bacterial infections, and they also function as cross-linkers to ensure the sustained release of basic fibroblast growth factor (bFGF). The potent antibacterial effect of the Ag NPs embedded in the hydrogel against S.aureus was validated through comprehensive in vitro and in vivo analyses. The microstructural analysis of the hydrogels and the in vitro release studies confirmed that the Ag NCH possesses smaller pore sizes and facilitates a slower, more sustained release of bFGF. When applied to acute and infected wound sites, the Ag NCH demonstrated remarkable capabilities in reshaping the immune and regenerative microenvironment. It induced a shift from M1 to M2 macrophage polarization, down-regulated the expression of pro-inflammatory factors such as IL-6 and TNF-α, and up-regulated the expression of anti-inflammatory IL-10. Furthermore, the Ag NCH played a crucial role in regulating collagen deposition and alignment, promoting the formation of mature blood vessels, and significantly enhancing tissue reconstruction and scarless wound healing processes.

CONCLUSIONS

We think the designed Ag NCH can provide a promising therapeutic strategy for clinical applications in scarless wound healing and antibacterial therapy.

Advancements in Composite Materials and Their Expanding Role in Biomedical Applications

The synthesis of a Ni-doped ZnO nanocomposite incorporating chitosan (CS/Ni-doped ZnO) was achieved via a precipitation method, followed by annealing at 250 °C. This study comprehensively examined the nanocomposite's structural, functional, morphological, and porosity properties using various analytical techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), high-resolution scanning electron microscopy (HR-SEM), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) analysis. The presence of chitosan (CS) and nickel (Ni) within the nanocomposite, along with their influence on reducing the band gap of ZnO particles and enhancing the generation of electron-hole pairs, was confirmed using UV-visible near-infrared spectroscopy (UV-vis-NIR). The electrochemical properties of the CS/Ni-doped ZnO nanocomposite were investigated via electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) by utilizing a phosphate buffer solution with a pH of 6, which closely resembled the typical pH of bacterial cell walls. Finally, the prepared CS/Ni-doped ZnO nanocomposite was evaluated for its antibacterial and anticancer activities. The results demonstrated the highest inhibition of bacterial growth in P. vulgaris, whereas the lowest inhibition was found in S. aureus across various concentrations, thus highlighting its potential in antimicrobial applications. The cytotoxicity of CS/Ni-doped ZnO nanocomposites demonstrated remarkable effects with a half-maximum inhibitory concentration of approximately 80 ± 0.23 µg mL-1 against MCF-7 breast cancer cell lines, following a dose-dependent manner.

Ceftazidime-assisted synthesis of ultrasmall chitosan nanoparticles for biofilm penetration and eradication of Pseudomonas aeruginosa

Pseudomonas aeruginosa (P. aeruginosa) infections present a grave threat to immunocompromised individuals, particularly those with cystic fibrosis due to the development of bacterial biofilms. In this study, we engineered self-assembling chitosan-ceftazidime nanoparticles (CSCE) capable of effectively penetrating biofilms and eradicating P. aeruginosa. The CSCE nanoparticles were synthesized through ionic cross-linking, combining negatively charged ceftazidime with positively charged chitosan, resulting in uniform nanoparticles measuring approximately 40 nm in diameter, exhibiting high dispersity and excellent biocompatibility. Remarkably, these nanoparticles exhibited significant inhibition of P. aeruginosa growth, reduced pyocyanin production, and diminished biofilm formation, achieving a maximum inhibition rate of 22.44%. Furthermore, in vivo investigations demonstrated enhanced survival in mice with abdominal P. aeruginosa infection following treatment with CSCE nanoparticles, accompanied by reduced levels of inflammatory cytokines Interleukin-6 (125.79 ± 18.63 pg/mL), Interleukin-17 (125.67 ± 5.94 pg/mL), and Tumor Necrosis Factor-α (135.4 ± 11.77 pg/mL). Critically, mice treated with CSCE nanoparticles showed no presence of bacteria in the bloodstream following intraperitoneal P. aeruginosa infection. Collectively, our findings highlight the potential of these synthesized nanoparticles as effective agents against P. aeruginosa infections.

Natural Polymeric Nanobiocomposites for Anti-Cancer Drug Delivery Therapeutics: A Recent Update

Cancer is one of the most common lethal diseases and the leading cause of mortality worldwide. Effective cancer treatment is a global problem, and subsequent advancements in nanomedicine are useful as substitute management for anti-cancer agents. Nanotechnology, which is gaining popularity, enables fast-expanding delivery methods in science for curing diseases in a site-specific approach, utilizing natural bioactive substances because several studies have established that natural plant-based bioactive compounds can improve the effectiveness of chemotherapy. Bioactive, in combination with nanotechnology, is an exceptionally alluring and recent development in the fight against cancer. Along with their nutritional advantages, natural bioactive chemicals may be used as chemotherapeutic medications to manage cancer. Alginate, starch, xanthan gum, pectin, guar gum, hyaluronic acid, gelatin, albumin, collagen, cellulose, chitosan, and other biopolymers have been employed successfully in the delivery of medicinal products to particular sites. Due to their biodegradability, natural polymeric nanobiocomposites have garnered much interest in developing novel anti-cancer drug delivery methods. There are several techniques to create biopolymer-based nanoparticle systems. However, these systems must be created in an affordable and environmentally sustainable way to be more readily available, selective, and less hazardous to increase treatment effectiveness. Thus, an extensive comprehension of the various facets and recent developments in natural polymeric nanobiocomposites utilized to deliver anti-cancer drugs is imperative. The present article provides an overview of the latest research and developments in natural polymeric nanobiocomposites, particularly emphasizing their applications in the controlled and targeted delivery of anti-cancer drugs.

Composite Hydrogels with Included Solid-State Nanoparticles Bearing Anticancer Chemotherapeutics

Hydrogels have many useful physicochemical properties which, in combination with their biocompatibility, suggest their application as a drug delivery system for the local and prorogated release of drugs. However, their drug-absorption capacity is limited because of the gel net's poor adsorption of hydrophilic molecules and in particular, hydrophobic molecules. The absorption capacity of hydrogels can be increased with the incorporation of nanoparticles due to their huge surface area. In this review, composite hydrogels (physical, covalent and injectable) with included hydrophobic and hydrophilic nanoparticles are considered as suitable for use as carriers of anticancer chemotherapeutics. The main focus is given to the surface properties of the nanoparticles (hydrophilicity/hydrophobicity and surface electric charge) formed from metal and dielectric substances: metals (gold, silver), metal-oxides (iron, aluminum, titanium, zirconium), silicates (quartz) and carbon (graphene). The physicochemical properties of the nanoparticles are emphasized in order to assist researchers in choosing appropriate nanoparticles for the adsorption of drugs with hydrophilic and hydrophobic organic molecules.

Bimetallic (Ag and MgO) nanoparticles, Aloe vera extracts loaded xanthan gum nanocomposite for enhanced antibacterial and in-vitro wound healing activity

We prepared nanocomposite (XG-AVE-Ag/MgO NCs) using the bimetallic Ag/MgO NPs, Aloe vera extract (AVE), and biopolymer (Xanthan gum (XG)) to archive a synergetic antibacterial and wound healing activity. The changes in XRD peaks at 20° of XG-AVE-Ag/MgO NCs indicated the XG encapsulation. The XG-AVE-Ag/MgO NCs showed the zeta potential and zeta size of 151.3 ± 3.14 d·nm and -15.2 ± 1.08 mV with a PDI of 0.265 while TEM showed an average size of 61.19 ± 3.89. The EDS confirmed the co-existence of Ag, Mg, carbon, oxygen, and nitrogen in NCs. XG-AVE-Ag/MgO NCs displayed higher antibacterial activity in terms of zone of inhibition, at 15.00 ± 0.12 mm for B. cereus and 14.50 ± 0.85 mm for E. coli. Moreover, NCs exhibited MICs of 2.5 μg/mL for E. coli, and 0.62 μg/mL for B. cereus. The in vitro cytotoxicity and hemolysis assays indicated the non-toxic properties of XG-AVE-Ag/MgO NCs. The higher wound closure activity was observed with the treatment of XG-AVE-Ag/MgO NCs (91.19 ± 1.87 %) compared to the control, untreated group (68.68 ± 3.54 %) at 48 h of incubation. These findings revealed that XG-AVE-Ag/MgO NCs was promising non-toxic, antibacterial, and wound-healing agent that deserved further in-vivo studies.

pH-sensitive biocompatible chitosan/sepiolite-based cross-linked citric acid magnetic nanocarrier for efficient sunitinib release

In this study, the magnetite nanoparticles were immobilized on the sepiolite needles via co-precipitation of iron ions. Then, the resulted magnetic sepiolite (mSep) nanoparticles were coated with chitosan biopolymer (Chito) in the presence of citric acid (CA) to prepare mSep@Chito core-shell drug nanocarriers (NCs). TEM images showed magnetic Fe₃O₄ nanoparticles with small sizes (less than 25 nm) on the sepiolite needles. Sunitinib anticancer drug loading efficiencies were ⁓45 and 83.7 % for the NCs with low and high content of Chito, respectively. The in-vitro drug release results exhibited that the mSep@Chito NCs have a sustained release behavior with high pH-dependent properties. Cytotoxic results (MTT assay) showed that the sunitinib-loaded mSep@Chito2 NC had a significant cytotoxic effect on the MCF-7 cell lines. Also, the in-vitro compatibility of erythrocytes, physiological stability, biodegradability, and antibacterial and antioxidant activities of NCs was evaluated. The results showed that the synthesized NCs had excellent hemocompatibility, good antioxidant properties, and were sufficiently stable and biocompatible. Based on the antibacterial data, the minimal inhibitory concentration (MIC) values for mSep@Chito1, mSep@Chito2, and mSep@Chito3 were obtained as 125, 62.5, and 31.2 μg/mL towards S. aureus, respectively. All in all, the prepared NCs could be potentially used as a pH-triggered system for biomedical applications.

Chitosan membrane drafting silver-immobilized graphene oxide nanocomposite for banana preservation: Fabrication, physicochemical properties, bioactivities, and application

In this study, silver-immobilized graphene oxide/chitosan (AGC/CTS) membranes were assembled by the solvent evaporation method, wherein Curcuma longa extract was used to synthesize silver-immobilized graphene oxide (AGC) nanocomposite. The characterization results showed that the AGC was successfully synthesized with AgNPs distributed quite evenly on GO sheets. The as-prepared AGC also exhibited high antibacterial activity and low cytotoxicity towards normal cell lines compared to human epithelial carcinoma cell lines. Besides, the fabrication of AGC/CTS membranes was additionally assessed with different AGC ratios and thicknesses. The results revealed the membrane containing 3 wt% of AGC with great hygroscopicity and elasticity module of 27.03 ± 3.07 MPa. The samples also performed excellent bactericidal capability, along with good mechanical properties for banana preservation. Therewithal, the membrane-coated bananas were also elucidated to be ripened at slower paces and less damage, with no appearance of patches of mold on the banana peel surface, eventually prolonging the shelf life of bananas up to 10 days as compared to the non-coated ones. The aforesaid results confirm the potential application of the AGC/CTS membrane as a safe and alternative fruit preservation agent in the food industry.

Chitosan/glycyrrhizic acid hydrogel: Preparation, characterization, and its potential for controlled release of gallic acid

In the present work, chitosan (CHT) as a biodegradable polymer was crosslinked using various amounts of glycyrrhizic acid (GLA) as a novel crosslinking agent to prepare biocompatible hydrogels. The prepared hydrogels were used for the controlled release of gallic acid (GA) in transdermal therapy application. FTIR, XRD, and SEM were used to characterize the prepared gels. The results indicated that the carboxylic acid groups of GLA react with the amine groups of the CHT in the presence of activating coupling reagents to form covalent amide linkage between the polymer chains of CHT and construct CHT cross-linked hydrogel (CCH) network structure. The prepared CCH samples were characterized and used for the controlled release of a drug, i.e. (GA). For this purpose, the swelling kinetic, loading and encapsulation efficiency, in vitro drug release, drug release kinetics, cell viability assay, and anti-bacterial activity of the samples were evaluated. The swelling ratio of CCH samples were in the range of 455-37 % depending on the pH of environment. Swelling kinetic results showed an aggregate to the non-linear second-order kinetic model. Drug release results were fitted by kinetic models while the Korsmeyer-Peppas model was fitted better. The CCH samples exhibited high biocompatibility for 5 mg/ml hydrogel concentration. In addition, the CHT and CCH sample without the GA did not show anti-bacterial properties for 1200 and 150 μg/ml concentrations, respectively. The CCH sample containing the GA exhibited enough anti-bacterial activity on the S. aureus bacteria strain at 150 μg/ml concentration. In contrast, the CCH sample containing the GA has a light anti-bacterial effect on the E. coli bacteria strain. The calculated mesh size of hydrogel networks, drug size, and kinetics models revealed that the CCH samples could release GA based on a diffusion mechanism. In conclusion, the designed CCH samples have enough ability for controlled drug release in transdermal applications.

Chitosan-based packaging films with an integrated antimicrobial peptide: Characterization, in vitro release and application to fresh pork preservation

Chitosan (CS) films were developed incorporating peptide HX-12C. The films were studied to determine their microstructures, physical properties, release properties of peptide HX-12C and functional properties. The results indicated that there may be hydrogen bonding interactions between CS and peptide HX-12C, thereby creating a homogeneous internal microstructure and lower crystallinity (10.8-12.8 %). Compared with CS film, CS-HX-12C films displayed lower light transmission, MC (20.8-19.9 %), WVP (8.82-8.59 × 10^-11·g·m^-1·s^-1·Pa^-1), OTR (0.015-0.037 cc/(m².day)) and higher WS (15.7-32.4 %) values. Moreover, controlled-release experiments showed that pH, ionic strength and temperature could all significantly affect the release of peptide HX-12C from the films. Finally, the increase of pH value and TVC and lipid oxidation of fresh pork were delayed due to the treatment with CS-2%HX-12C film. However, incorporating peptide HX-12C into CS films did not improve the mechanical properties of the films and their effects against protein oxidation. Our results suggest that the CS-based antimicrobial packaging films integrated with peptide HX-12C exhibit the potential for fresh pork preservation.

Knowledge mapping concerning applications of nanocomposite hydrogels for drug delivery: A bibliometric and visualized study (2003-2022)

Background: Nanocomposite Hydrogels (NHs) are 3D molecular networks formed by physically or covalently crosslinking polymer with nanoparticles or nanostructures, which are particularly suitable for serving as carriers for drug delivery systems. Many articles pertaining to the applications of Nanocomposite Hydrogels for drug delivery have been published, however, the use of bibliometric and visualized analysis in this area remains unstudied. The purpose of this bibliometric study intended to comprehensively analyze the knowledge domain, research hotspots and frontiers associated with the applications of Nanocomposite Hydrogels for drug delivery. Methods: We identified and retrieved the publications concerning the applications of NHs for drug delivery between 2003 and 2022 from Web of Science Core Collection Bibliometric and visualized analysis was utilized in this investigative study. Results: 631 articles meeting the inclusion criteria were identified and retrieved from WoSCC. Among those, 2,233 authors worldwide contributed in the studies, accompanied by an average annual article increase of 24.67%. The articles were co-authored by 764 institutions from 52 countries/regions, and China published the most, followed by Iran and the United States. Five institutions published more than 40 papers, namely Univ Tabriz (n = 79), Tabriz Univ Med Sci (n = 70), Islamic Azad Univ (n = 49), Payame Noor Univ (n = 42) and Texas A&M Univ (n = 41). The articles were published in 198 journals, among which the International Journal of Biological Macromolecules (n = 53) published the most articles, followed by Carbohydrate Polymers (n = 24) and ACS Applied Materials and Interfaces (n = 22). The top three journals most locally cited were Carbohydrate Polymers, Biomaterials and Advanced materials. The most productive author was Namazi H (29 articles), followed by Bardajee G (15 articles) and Zhang J (11 articles) and the researchers who worked closely with other ones usually published more papers. "Doxorubicin," "antibacterial" and "responsive hydrogels" represent the current research hotspots in this field and "cancer therapy" was a rising research topic in recent years. "(cancer) therapeutics" and "bioadhesive" represent the current research frontiers. Conclusion: This bibliometric and visualized analysis offered an investigative study and comprehensive understanding of publications regarding the applications of Nanocomposite Hydrogels for drug delivery from 2003 to 2022. The outcome of this study would provide insights for researchers in the field of Nanocomposite Hydrogels applications for drug delivery.

Chitosan-based nanoscale systems for doxorubicin delivery: Exploring biomedical application in cancer therapy

Green chemistry has been a growing multidisciplinary field in recent years showing great promise in biomedical applications, especially for cancer therapy. Chitosan (CS) is an abundant biopolymer derived from chitin and is present in insects and fungi. This polysaccharide has favorable characteristics, including biocompatibility, biodegradability, and ease of modification by enzymes and chemicals. CS-based nanoparticles (CS-NPs) have shown potential in the treatment of cancer and other diseases, affording targeted delivery and overcoming drug resistance. The current review emphasizes on the application of CS-NPs for the delivery of a chemotherapeutic agent, doxorubicin (DOX), in cancer therapy as they promote internalization of DOX in cancer cells and prevent the activity of P-glycoprotein (P-gp) to reverse drug resistance. These nanoarchitectures can provide co-delivery of DOX with antitumor agents such as curcumin and cisplatin to induce synergistic cancer therapy. Furthermore, co-loading of DOX with siRNA, shRNA, and miRNA can suppress tumor progression and provide chemosensitivity. Various nanostructures, including lipid-, carbon-, polymeric- and metal-based nanoparticles, are modifiable with CS for DOX delivery, while functionalization of CS-NPs with ligands such as hyaluronic acid promotes selectivity toward tumor cells and prevents DOX resistance. The CS-NPs demonstrate high encapsulation efficiency and due to protonation of amine groups of CS, pH-sensitive release of DOX can occur. Furthermore, redox- and light-responsive CS-NPs have been prepared for DOX delivery in cancer treatment. Leveraging these characteristics and in view of the biocompatibility of CS-NPs, we expect to soon see significant progress towards clinical translation.

Natural Polymer-Based Graphene Oxide Bio-nanocomposite Hydrogel Beads: Superstructures with Advanced Potentials for Drug Delivery

The current study sought to create graphene oxide-based superstructures for gastrointestinal drug delivery. Graphene oxide has a large surface area that can be used to load anti-cancer drugs via non-covalent methods such as surface adsorption and hydrogen bonding. To enhance the bio-applicability of graphene oxide, nano-hybrids were synthesized by encapsulating the graphene oxide into calcium alginate hydrogel beads through the dripping-extrusion technique. These newly developed bio-nanocomposite hybrid hydrogel beads were evaluated in structural analysis, swelling study, drug release parameters, haemolytic assay, and antibacterial activity. Doxorubicin served as a model drug. The drug entrapment efficiency was determined by UV-spectroscopy analysis and was found to be high at ⁓89% in graphene oxide hybrid hydrogel beads. These fabricated hydrogel beads ensure the drug release from a hybrid polymeric matrix in a more controlled and sustained pattern avoiding the problems associated with a non-hybrid polymeric system. The drug release study of 12 h shows about 83% release at pH 6.8. In vitro drug release kinetics proved that drug release was a Fickian mechanism. The cytotoxic effect of graphene oxide hybrid alginate beads was also determined by evaluating the morphology of bacterial cells and red blood cells after incubation. Additionally, it was determined that the sequential encapsulation of graphene oxide in alginate hydrogel beads hides its uneven edges and lessens the graphene oxide's negative impacts. Also, the antibacterial study and biocompatibility of fabricated hydrogel beads made them potential candidates for gastrointestinal delivery.

In Vivo and In Silico Investigation of the Anti-Obesity Effects of Lactiplantibacillus plantarum Combined with Chia Seeds, Green Tea, and Chitosan in Alleviating Hyperlipidemia and Inflammation

The increasing prevalence of obesity has become a demanding issue in both high-income and low-income countries. Treating obesity is challenging as the treatment options have many limitations. Recently, diet modification has been commonly applied to control or prevent obesity and its risks. In this study, we investigated novel therapeutic approaches using a combination of a potential probiotic source with prebiotics. Forty-eight adult male Sprague-Dawley rats were selected and divided into seven groups (eight rats per group). The first group was fed a high-fat diet, while the second group was a negative control. The other five groups were orally administered with a probiotic, Lactiplantibacillus plantarum (L. plantarum), and potential prebiotics sources (chia seeds, green tea, and chitosan) either individually or in combination for 45 days. We collected blood samples to analyze the biochemical parameters and dissected organs, including the liver, kidney, and pancreas, to evaluate obesity-related injuries. We observed a more significant decrease in the total body weight by combining these approaches than with individual agents. Moreover, treating the obese rats with this combination decreased serum catalase, superoxide dismutase, and liver malondialdehyde levels. A histopathological examination revealed a reduction in obesity-related injuries in the liver, kidney, and pancreas. Further docking studies indicated the potential role of chia seeds and green tea components in modulating obesity and its related problems. Therefore, we suggest that the daily administration of a pre- and probiotic combination may reduce obesity and its related problems.

Polymer-Based Hybrid Nanoarchitectures for Cancer Therapy Applications

Globally, cancer is affecting societies and is becoming an important cause of death. Chemotherapy can be highly effective, but it is associated with certain problems, such as undesired targeting and multidrug resistance. The other advanced therapies, such as gene therapy and peptide therapy, do not prove to be effective without a proper delivery medium. Polymer-based hybrid nanoarchitectures have enormous potential in drug delivery. The polymers used in these nanohybrids (NHs) provide them with their distinct properties and also enable the controlled release of the drugs. This review features the recent use of polymers in the preparation of different nanohybrids for cancer therapy published since 2015 in some reputed journals. The polymeric nanohybrids provide an advantage in drug delivery with the controlled and targeted delivery of a payload and the irradiation of cancer by chemotherapeutical and photodynamic therapy.

Green starch/graphene oxide hydrogel nanocomposites for sustained release applications

Green nanocomposite hydrogels (ST-PHEMA/GO) comprised of starch and 2-Hydroxyethyl methacrylate (HEMA) reinforced with different ratios of graphene oxide (GO) were prepared via gamma radiation induced crosslinking polymerization. The chemical structure and morphology and the crystallinity were studied by FTIR FE-SEM, AFM, TEM and XRD, respectively. The swelling behavior of the claimed hydrogels was verified versus time and the pH-dependent swelling at three different irradiation dose:10, 20 and 30 kGy was also investigated. The results of the swelling study showed that the swelling capacity of the hydrogel networks varied with the changes of the pH of the solution, the GO content and the irradiation doses. Moreover, the swelling isotherm of all the prepared hydrogels followed a Fickian diffusion mechanism n < 0.5.

Graphical abstract

Biomedical applications of chitosan-graphene oxide nanocomposites

Chitosan (CS) and graphene oxide (GO) nanocomposites have received wide attention in biomedical fields due to the synergistic effect between CS which has excellent biological characteristics and GO which owns great physicochemical, mechanical, and optical properties. Nanocomposites based on CS and GO can be fabricated into a variety of forms, such as nanoparticles, hydrogels, scaffolds, films, and nanofibers. Thanks to the ease of functionalization, the performance of these nanocomposites in different forms can be further improved by introducing other functional polymers, nanoparticles, or growth factors. With this background, the current review summarizes the latest developments of CS-GO nanocomposites in different forms and compositions in biomedical applications including drug and biomacromolecules delivery, wound healing, bone tissue engineering, and biosensors. Future improving directions and challenges for clinical practice are proposed as well.

Chitosan coated Fe3O4@Cd-MOF microspheres as an effective adsorbent for the removal of the amoxicillin from aqueous solution

In this work, for the first time, a new magnetic cadmium-based MOFs (Fe₃O₄@Cd-MOF) was successfully synthesized in a green way and then modified with chitosan (CS) in the microsphere form (Fe₃O₄@Cd-MOF@CS). The obtained materials were fully characterized by several techniques. In the following, the efficiency of Fe₃O₄@Cd-MOF@CS was explored for the removal of amoxicillin (AMX). The outcome of the adsorption study showed that the removal efficiency is affected by CS and reaches its optimum at pH 8 and contact time of 240 min. Under optimized conditions, over 75% of AMX was removed. The kinetic and the isotherm of the adsorption were fit with the pseudo-second-order model and the Langmuir adsorption isotherm respectively. Eventually, the maximum adsorption capacity was obtained ~103.09 mg/g. Interestingly, these findings convince that the newly prepared Fe₃O₄@Cd-MOF@CS could be proposed as a promising magnetically separable adsorbent for antibiotic contaminants removal from the aqueous solution.

Introducing a flexible drug delivery system based on poly(glycerol sebacate)-urethane and its nanocomposite: potential application in the prevention and treatment of oral diseases

In this study, a novel biopolymer based on poly(glycerol sebacic)-urethane (PGS-U) and its nanocomposites containing Cloisite@30B were synthesized by facile approach in which the crosslinking was created by aliphatic hexamethylene diisocyanate (HDI) at room temperature and 80 °C. Moreover, metronidazole and tetracycline drugs were selected as target drugs and loaded into PGSU based nanocomposites. A uniform and continuous microstructure with smooth surface is observed in the case of pristine PGS-U sample. The continuity of microstructure is observed in the case of all bionanocomposites. XRD result confirmed an intercalated morphology for PGSU containing 5 wt% of clay nanoparticles with a d-spacing 3.4 nm. The increment of nanoclay content up to 5%, the ultimate tensile stress and elastic modulus were obtained nearly 0.32 and 0.83 MPa, which the latter was more than eight-fold than that of pristine PGS-U. A sustained release for both dugs was observed by 200 h. The slowest and controlled drug release rate was determined in the case of PGSU containing 5 wt% clay and cured at 80 °C. A non-Fickian diffusion can be concluded in the case of tetracycline release via PGS-U/nanoclay bionanocomposites, while a Fickian process was detected in the case of metronidazole release by PGS-U/nanoclay bionanocomposites. As a result, the designed scaffold showed high flexibility, which makes it an appropriate option for utilization in the treatment of periodontal disease.

Near-Infrared Light-Triggered Unfolding Microneedle Patch for Minimally Invasive Treatment of Myocardial Ischemia

It is hard to achieve safe, effective, and minimally invasive therapies on myocardial infarction (MI) via conventional treatments. To address this challenge, a vascular endothelial growth factor (VEGF)-loaded and near-infrared (NIR)-triggered self-unfolding graphene oxide (GO)-poly(vinyl alcohol) (PVA) microneedle (MN) patch was designed and fabricated to treat MI through a minimally invasive surgery (MIS). The folded MN patch can be easily placed into the chest cavity through a small cut (4 mm) and quickly recover to its original shape with 10 s of irradiation of NIR light (1.5 W/cm², beam diameter = 0.5 cm), thanks to its excellent shape memory effect and fast shape recovery ability. Meanwhile, the unfolded MN patch can be readily punctured into the heart and wrap the heart tightly, thanks to its sufficient mechanical strength and adjustable morphological structure, thus ensuring a high fixation strength to withstand the high-frequency pulsation of the heart. In addition, the prepared MN patch has low cytotoxicity and controllable and sustainable release of VEGF. More importantly, the MN patch can effectively promote neovascularization, reduce myocardial fibrosis, and restore cardiac function, which indicates its promising application prospects in MIS.

Injectable Nanocomposite Hydrogels for Cancer Therapy

Hydrogel is a kind of 3D polymer network with strong swelling ability in water and appropriate mechanical and biological properties, which make it feasible to maintain bioactive substances and has promising applications in the fields of biomaterials, soft machines, and artificial tissues. Unfortunately, traditional hydrogels prepared by chemical crosslinking have poor mechanical properties and limited functions, which limit their further application. In recent years, with the continuous development of nanoparticle research, more and more studies have combined nanoparticles with hydrogels to make up for the shortcomings of traditional hydrogels. In this article, the types and functions of hydrogels and nanomaterials are introduced first, as well as the functions and applications of injectable nanocomposite hydrogels (INHs), then the latest progress of INHs for cancer treatment is reviewed, some existing problems are summarized, and the application prospect of NHs is prospected.

Antibacterial metals and alloys for potential biomedical implants

Metals and alloys, including stainless steel, titanium and its alloys, cobalt alloys, and other metals and alloys have been widely used clinically as implant materials, but implant-related infection or inflammation is still one of the main causes of implantation failure. The bacterial infection or inflammation that seriously threatens human health has already become a worldwide complaint. Antibacterial metals and alloys recently have attracted wide attention for their long-term stable antibacterial ability, good mechanical properties and good biocompatibility in vitro and in vivo. In this review, common antibacterial alloying elements, antibacterial standards and testing methods were introduced. Recent developments in the design and manufacturing of antibacterial metal alloys containing various antibacterial agents were described in detail, including antibacterial stainless steel, antibacterial titanium alloy, antibacterial zinc and alloy, antibacterial magnesium and alloy, antibacterial cobalt alloy, and other antibacterial metals and alloys. Researches on the antibacterial properties, mechanical properties, corrosion resistance and biocompatibility of antibacterial metals and alloys have been summarized in detail for the first time. It is hoped that this review could help researchers understand the development of antibacterial alloys in a timely manner, thereby could promote the development of antibacterial metal alloys and the clinical application.

Facile Synthesis of the Cu, N-CDs@GO-CS Hydrogel with Enhanced Antibacterial Activity for Effective Treatment of Wound Infection

Drug resistance and increasing dangers during antibiotic treatment have brought a new eternal task for the research of effective antibacterial agents or therapeutics. In this work, we used Cu, N-doped carbon dots (Cu, N-CDs) to modify graphene oxide (GO) nanosheets and then loaded to chitosan (CS) hydrogels via electrostatic interaction to form Cu, N-CDs@GO-CS hydrogel nanoplatforms to treat Staphylococcus aureus and Escherichia coli. The excellent antibacterial activity is from the combined effects of hyperthermia and reactive oxygen species generated under near-infrared (NIR) laser irradiation of the Cu, N-CDs@GO-CS hydrogel, which shows excellent antibacterial activity compared with the CS hydrogel or the Cu, N-CDs@GO-CS hydrogel without NIR laser irradiation. Moreover, the inherent antibacterial nature of the CS hydrogel or the Cu, N-CDs@GO-CS hydrogel was used to treat bacteria-infected wounds in mice, which also protected the wound area from second infection. In vivo experiments demonstrate favorable wound healing results and have no significant harmful side effects to the major organs in mice. Overall, this work demonstrates that the antibacterial Cu, N-CDs@GO-CS hydrogel offers significant prospect as an antibacterial reagent for wound healing.

In vivo toxicity and antitumor activity of newly green synthesized reduced graphene oxide/silver nanocomposites

A novel biosynthesis of dual reduced graphene oxide/silver nanocomposites (rGO/AgNC) using the crude metabolite of Escherichia coli D8 (MF06257) strain and sunlight is introduced in this work. Physicochemical analysis of these rGO/AgNC revealed that they are sheet-like structures having spherically shaped silver nanoparticles (AgNPs) with an average particle size of 8 to 17 nm, and their absorption peak ranged from 350 to 450 nm. The biosynthesized rGO/AgNC were characterized by UV-vis and FT-IR spectra, X-ray diffraction, Zeta potential and transmission electron microscopy. After the injection of these nanocomposites to mice, their uptake by the kidney and liver has been proven by the ultrastructural observation and estimation of the hepatic and renal silver content. These nanocomposites caused a moderate toxicity for both organs. Changes in the liver and kidney functions and histopathological effects had been observed. The rGO/AgNC revealed a remarkable antitumor effect. They showed a dose-dependent cytotoxic effect on Ehrlich ascites carcinoma (EAC) cells in vitro. Treatment of mice bearing EAC tumors intraperitoneally with 10 mg/kg rGO/AgNC showed an antiproliferative effect on EAC cells, reduced ascites volume, and maintained mice survival. The results indicate that this green synergy of silver nanoparticles with reduced graphene oxide may have a promising potential in cancer therapy.

Thermally induced and physically cross-linked hydrogel doped with graphene oxide for controlled release

Graphene oxide (GO) is an ideal hydrogel material because of its water solubility, non-toxicity, and excellent mechanical properties. Here, we added GO to oligo(lysine)-modified F127 to prepare a series of FLGO composite hydrogels. The FLGO hydrogel was thermally induced, stable and injectable. And the content of GO would affect the sol-gel transition, rheological properties and glass transition temperature of the FLGO hydrogel. GO was connected to the matrix through electrostatic interactions and hydrogen bonds. The cross-linking effect of GO enhanced the FLGO hydrogel. We also studied the release properties of the FLGO hydrogel loaded with anticancer drug 5-fluorouracil. Compared with F127 hydrogel, the FLGO hydrogel showed a linear, slower and stable release pattern within one week. The release rate of FLGO hydrogel could be adjusted by the pH and it was faster under acidic conditions. Therefore, the FLGO hydrogel is expected to be used as a drug release system in the field of biomedicine.

Synergistic antibacterial activity of surfactant free Ag-GO nanocomposites

Graphene oxide–silver (Ag–GO) nanocomposite has emerged as a vital antibacterial agent very recently. In this work, we report a facile one step route of Ag–GO nanocomposite formation excluding the aid of surfactants and reductants and was successfully applied to negative Escherichia Coli (E coli) to investigate antibacterial activity by varying doze concentration. The successful formation of Ag–GO nanocomposite via facile one step route was confirmed using Fourier transform infrared spectroscopy (FTIR) and Raman Spectroscopy. The absorption spectra (peak ~ 300 nm) for GO and the (peak ~ 420 nm) for silver nanoparticles were observed. XRD study confirmed the formation of Ag–GO nanocomposite while atomic force microscopy (AFM) showed crumbled GO sheets decorated with Ag nanoparticles. It was observed that the functional groups of GO facilitated the binding of Ag nanoparticles to GO network and enhanced the antibacterial activity of the nanocomposite.

A photoluminescent folic acid-derived carbon dot functionalized magnetic dendrimer as a pH-responsive carrier for targeted doxorubicin delivery

A fluorescent folic acid carbon dot-grafted magnetic dendrimer was synthesized as a potential carrier for targeted delivery of DOX drug in an acidic medium (pH 5). The carrier showed biodegradability, high colloidal stability, and good biocompatibility towards A549 cells.

Graphene Oxide as a Nanocarrier for Biochemical Molecules: Current Understanding and Trends

The development of an advanced and efficient drug delivery system with significant improvement in its efficacy and enhanced therapeutic value is one of the critical challenges in modern medicinal biology. The integration of nanomaterial science with molecular and cellular biology has helped in the advancement and development of novel drug delivery nanocarrier systems with precision and decreased side effects. The design and synthesis of nanocarriers using graphene oxide (GO) have been rapidly growing over the past few years. Due to its remarkable physicochemical properties, GO has been extensively used in efforts to construct nanocarriers with high specificity, selectivity, and biocompatibility, and low cytotoxicity. The focus of this review is to summarize and address recent uses of GO-based nanocarriers and the improvements as efficient drug delivery systems. We briefly describe the concepts and challenges associated with nanocarrier systems followed by providing critical examples of GO-based delivery of drug molecules and genes. Finally, the review delivers brief conclusions on the current understanding and prospects of nanocarrier delivery systems.

Engineering Smart Targeting Nanovesicles and Their Combination with Hydrogels for Controlled Drug Delivery

Smart engineered and naturally derived nanovesicles, capable of targeting specific tissues and cells and delivering bioactive molecules and drugs into them, are becoming important drug delivery systems. Liposomes stand out among different types of self-assembled nanovesicles, because of their amphiphilicity and non-toxic nature. By modifying their surfaces, liposomes can become stimulus-responsive, releasing their cargo on demand. Recently, the recognized role of exosomes in cell-cell communication and their ability to diffuse through tissues to find target cells have led to an increase in their usage as smart delivery systems. Moreover, engineering "smarter" delivery systems can be done by creating hybrid exosome-liposome nanocarriers via membrane fusion. These systems can be loaded in naturally derived hydrogels to achieve sustained and controlled drug delivery. Here, the focus is on evaluating the smart behavior of liposomes and exosomes, the fabrication of hybrid exosome-liposome nanovesicles, and the controlled delivery and routes of administration of a hydrogel matrix for drug delivery systems.

Antibacterial Hybrid Hydrogels

Bacterial infectious diseases and bacterial-infected environments have been threatening the health of human beings all over the world. In view of the increased bacteria resistance caused by overuse or improper use of antibiotics, antibacterial biomaterials are developed as the substitutes for antibiotics in some cases. Among them, antibacterial hydrogels are attracting more and more attention due to easy preparation process and diversity of structures by changing their chemical cross-linkers via covalent bonds or noncovalent physical interactions, which can endow them with various specific functions such as high toughness and stretchability, injectability, self-healing, tissue adhesiveness and rapid hemostasis, easy loading and controlled drug release, superior biocompatibility and antioxidation as well as good conductivity. In this review, the recent progress of antibacterial hydrogel including the fabrication methodologies, interior structures, performances, antibacterial mechanisms, and applications of various antibacterial hydrogels is summarized. According to the bacteria-killing modes of hydrogels, several representative hydrogels such as silver nanoparticles-based hydrogel, photoresponsive hydrogel including photothermal and photocatalytic, self-bacteria-killing hydrogel such as inherent antibacterial peptides and cationic polymers, and antibiotics-loading hydrogel are focused on. Furthermore, current challenges of antibacterial hydrogels are discussed and future perspectives in this field are also proposed.