Chitosan Nanogels Research Articles

Thermo sensitive and pH responsive surface modulated transdermal green tea nanogel: Structural, physiochemical and in vitro safety investigations

An altered simplistic biomimetic whole green tea extract-loaded nanogel (GE-C-NGL) was fabricated possessing pH-responsive and temperature-dependent intracellular transdermal nanotherapy. A biocompatible chitosan nanogel subsequently surface modified with oleic acid aiding Pluronic 127 discharging green tea extract on transdermal delivery was evaluated in light of structural, physiochemical, thermal, and in vitro toxicological factors by optical class, index class and spectrophotometrically class, and in vitro cell line toxicological evaluations, which precisely elaborated the nanosize particle size range and significant drug entrapment suggesting a spherical and thermo stable nanogel system. Additionally, sustained drug release configuration is displayed in mildly acidic conditions (pH 6) signifying ultra-pH sensitivity of GE-C-NGL. Moreover, strong mucin binding ability, pH-dependent swelling efficiency, negligible hemolytic ratio, and high antioxidant activity were obtained for enhanced transdermal efficacy. The comprehensive augmented polymeric blend transdermal nanogel, in light of the above preclinical biological and toxicological evaluations, evidently targets transdermal potential with promising bacterial biodegradable nanodrug therapy in clinical platforms.

Effect of chitosan nanogels loaded with vancomycin and gamma interferon on TNF-α gene expression in macrophage cell line activated with methicillin-resistant Staphylococcus aureus (MRSA).

Staphylococcus aureus is an opportunistic pathogen that frequently leads to asymptomatic infections. Methicillin-resistant strains (MRSA) pose a significant threat as they are resistant to most commonly used antibiotics, complicating treatment efforts. This study aimed to develop chitosan nanogels loaded with vancomycin and IFN-γ and to assess the expression of the TNF-α gene in a cell line infected with MRSA. Following the synthesis and confirmation of the chitosan nanogels, vancomycin and IFN-γ were incorporated into these nanogels. The synthesis was validated using DLS, FTIR, TEM, and SEM. Subsequently, the anti-bacterial efficacy of the nanogels was assessed. Finally, four groups of cell lines were designed: control, MRSA, chitosan nanogels and IFN-γ-vancomycin chitosan nanogels. After infection of the groups (except control) with MRSA, 5 μg/mL of nanogels, and nanogels (drug and IFN-γ) were added to groups 3 and 4, respectively. Then the expression of TNF-α gene in each group was analyzed by RT-PCR at 6 and 24 hours. At pH 6.5 and 7.4, the MIC of 1 μg/mL was obtained for free vancomycin, whereas that of IFN-γ-vancomycin nanogels at both pHs was respectively 8 and 64 μg/mL. The IC50 of chitosan nanogels and nanogels loaded with vancomycin-IFN-γ on RAW264.7 cells were 2.37 and 4.15 μg/mL in 24 hours, respectively. In group 4 in comparison to the MRSA group, TNF-α expression decreased significantly following 24 hours. Loading of vancomycin and IFN-γ in the chitosan nanogel can reduce TNF-α gene expression on MRSA infected cell lines.

Injectable nanogels to improve triamcinolone acetonide delivery and toxicity on the treatment of eye diseases.

Triamcinolone acetonide (TA) is a corticosteroid, and widely used in the treatment of eye diseases such as macular edema, proliferative vitreoretinopathy, and chronic uveitis. It's also used in diseases such as osteoarthritis and rheumatoid arthritis. Despite the width of its usage, it has toxicity in the eye. Nanogels are advantageous in applying toxic and low bioavailability drugs thanks to their swelling ability and stability. In the presented study, to minimize the disadvantages of TA, and to reach the drug into the back segment of the eye, TA-loaded chitosan (CS) nanogel (CS-TA Nanogel) has been prepared, and in vitro characterized. CS-TA nanogels were prepared by ionic gelation and characterized by SEM, FTIR, and TGA. Drug release profile, and in vitro cytotoxicity was determined to evaluate the efficacy of nanogels for intravitreal eye applications. DNA damage, and oxidative stress caused by nanogels in eye endothelial cells were investigated. CS and CS-TA nanogels were synthesized in the sizes range 200-300nm with an overall positive charge surface. The loading efficiency of TA on nanogels was determined as 50%. Cells exposed to 250µg/ml free TA showed 74% viability, while this rate was 90% in cells exposed to CS-TA nanogels. 8-OHdG levels were determined as 54.93 ± 1.118ng/mL in control cells and 92.47 ± 0.852ng/mL in cells exposed to 250µg/ml TA. TA both induces oxidative stress and causes DNA damage in HRMEC cells. However, administration of TA with carrier increased cell viability, total antioxidant capacity, and reduced oxidative DNA damage.

Trinitroglycerin-loaded chitosan nanogels accelerate angiogenesis in wound healing process

Trinitroglycerin (TNG) with remarkable angiogenic, antibacterial, and antioxidative activity is a promising candidate to govern wound healing capacity. However, its clinical administration is limited due to associated complications and NO short half-life. In the current study, TNG-loaded chitosan nanogels (TNG-Ngs) were examined in-vitro and in-vivo to gain insight into their clinical application. We prepared TNG-Ngs and characterized their physiochemical properties. The potential of TNG-Ngs was assessed using biocompatibility, scratch assay, and a full-thickness skin wounds model, followed by histopathological and immunohistochemistry examinations. TNG-Ngs particle size 96 ± 18 and definite size distribution histogram. The loading capacity (LC) and encapsulation efficiency (EE) of prepared TNG-Ngs were 70.2 % and 2.1 %, respectively. The TNG-Ngs samples showed enhanced migration of HUVECs with no apparent cytotoxicity. The topical use of TNG-Ngs200 on the wounds revealed a complete wound closure ratio, skin component formation, less scar width, remarkable granulation tissue, promoted collagen deposition, and enhanced the relative mean density of α-SMA and CD31. TNG-Ngs accelerated wound healing by promoting collagen deposition and angiogenic activity, as well as reducing inflammation. The findings indicated that TNG-Ngs is expected to be well vascularized in the wound area and to be more effective in topical therapy.

Pengaruh Penambahan Kitosan Nano Gel Bermolekul Sedang pada Bahan Basis Gigi Tiruan Resin Akrilik Polimerisasi Panas Terhadap Kekuatan Transversal

Hot polymerized acrylic resin is one of the most widely used denture base materials, but this material has low transverse strength so it is easy to fracture. Transverse strength can be increased by adding reinforcing material Chitosan nano gel which is proven to increase transverse strength because the Chitosan nano gel has special properties such as biodegradability, biocompatibility, good mechanical properties and good layer formation properties. The purpose of this study was to determine the effect of adding Chitosan nano gel to heat polymerized acrylic resin denture base material on the transverse strength. The research design used in this study was an experimental laboratory. The research sample was a rectangular hot polymerized acrylic resin with a size of 65 mm x 10 mm x 2.5 mm±0. 5 for the calculation of transverse strength with a total sample of 27 samples. The results of this study indicate that the value of transverse strength added with 1.25% Chitosan nano gel is the most effective concentration to increase the transverse strength of the heat polymerized acrylic resin denture base material compared to the addition of 1% Chitosan nano gel and without the addition of chitosan nano gel.

An Investigation into the Effects of Processing Factors on the Properties and Scaling-Up Potential of Propranolol-Loaded Chitosan Nanogels.

Chitosan-triphosphate (TPP) nanogels are widely studied drug delivery carrier systems, typically prepared via a simple mixing process. However, the effects of the processing factors on nanogel production have not been extensively explored, despite the importance of understanding and standardising such factors to allow upscaling and commercial usage. This study aims to systematically evaluate the effects of various fabrication and processing factors on the properties of nanogels using a Design of Experiment approach. Hydrodynamic size, polydispersity index (PDI), zeta potential, and encapsulation efficiency were determined as the dependent factors. The temperature, stirring rate, chitosan grade, crosslinker choice, and the interaction term between temperature and chitosan grade were found to have a significant effect on the particle size, whereas the effect of temperature and the addition rate of crosslinker on the PDI was also noteworthy. Moreover, the addition rate of the crosslinker and the volume of the reaction vessel were found to impact the encapsulation efficiency. The zeta potential of the nanogels was found to be governed by the chitosan grade. The optimal fabrication conditions for the development of medium molecular weight chitosan and TPP nanogels included the following: the addition rate for TPP solution was set at 2 mL/min, while the solution was then stirred at a temperature of 50 °C and a stirring speed of 600 rpm. The volume of the glass vial used was 28 mL, while the stirrer size was 20 mm. The second aim of the study was to evaluate the potential for scaling up the nanogels. Size and PDI were found to increase from 128 nm to 151 nm and from 0.232 to 0.267, respectively, when the volume of the reaction mixture was increased from 4 to 20 mL and other processing factors were kept unchanged. These results indicate that caution is required when scaling up as the nanogel properties may be significantly altered with an increasing production scale.

Biomimetic nanodrug blocks CD73 to inhibit adenosine and boosts antitumor immune response synergically with photothermal stimulation

Combination of tumor immunotherapy with photothermal therapy (PTT) is a feasible tactic to overcome the drawback of immunotherapy such as poor immune response. Via triggering the immunogenic cells death (ICD), PTT can stimulate the activity of immune cells, but meanwhile, the level of adenosine is elevated via the CD73-induced decomposition of ATP which is overexpressed accompanying with the PTT process, resulting in negative feedback to impair the immune stimulation. Herein, we developed a novel biomimetic photothermal nanodrug to specifically block CD73 for inhibition of adenosine production and more efficient priming of the suppressive immune microenvironments. The nanodrug, named as AptEM@CBA, is constructed by encapsulation of photothermal agent black phosphorus quantum dots (BPQDs) and selective CD73 inhibitor α, β-Methyleneadenosine 5′-diphosphate (AMPCP) in chitosan nanogels, which are further covered with aptamer AS1411 modified erythrocyte membrane (EM) for biomimetic camouflage. With AS1411 induced active targeting and EM induced long blood circulation time, the enrichment of the nanodrug tumor sites is promoted. The photothermal treatment promotes the maturation of dendritic cells. Meanwhile, the release of AMPCP suppress the adenosine generation via CD73 blockade, alleviating the impairment of adenosine to dendritic cells and suppressing regulatory T cells, synergically stimulate the activity of T cells. The combination of CD73 blockade with PTT, not only suppresses the growth of primary implanted tumors, but also boosts strong antitumor immunity to inhibit the growth of distal tumors, providing good potential for tumor photoimmunotherapy.

Anticancer potential of thiocolchicoside and lauric acid loaded chitosan nanogel against oral cancer cell lines: a comprehensive study

The present study explored the anticancer activity of a Chitosan-based nanogel incorporating thiocolchicoside and lauric acid (CTL) against oral cancer cell lines (KB-1). Cell viability, AO/EtBr dual staining and Cell cycle analysis were done to evaluate the impact of CTL nanogel on oral cancer cells. Real-time PCR was performed to analyze proapoptotic and antiapoptotic gene expression in CTL-treated KB-1 cells. Further, molecular docking analysis was conducted to explore the interaction of our key ingredient, thiocolchicoside and its binding affinities. The CTL nanogel demonstrated potent anticancer activity by inhibiting oral cancer cell proliferation and inducing cell cycle arrest in cancer cells. Gene expression analysis indicated alterations in Bax and Bcl-2 genes; CTL nanogel treatment increased Bax mRNA expression and inhibited the Bcl-2 mRNA expression, which showed potential mechanisms of the CTL nanogel's anticancer action. It was found that thiocolchicoside can stabilize the protein's function or restore it as a tumour suppressor. The CTL nanogel exhibited excellent cytotoxicity and potent anticancer effects, making it a potential candidate for non-toxic chemotherapy in cancer nanomedicine. Furthermore, the nanogel's ability to modulate proapoptotic gene expression highlights its potential for targeted cancer therapy. This research contributes to the growing interest in Chitosan-based nanogels and their potential applications in cancer treatment.

Co-encapsulation of Shirazi thyme (Zataria multiflora) essential oil and nisin using caffeic acid grafted chitosan nanogel and the effect of this nanogel as a bio-preservative in Iranian white cheese.

The current study aims to co-encapsulate Shirazi thyme (Zataria multiflora) essential oil (ZEO) and nisin into chitosan nanogel as an antimicrobial and antioxidant agent to enhance the shelf-life of cheese. Chitosan-caffeic acid (CS-CA) nanogel was produced to co-encapsulate Zataria multiflora essential oil and nisin. This nanogel was characterized by dynamic light scattering (DLS), Fourier Transform Infrared (FTIR) spectroscopic analysis, X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM) images. The effect of free (TFZN) and encapsulated ZEO-nisin in chitosan nanogel (TCZN) on the chemical and microbiological properties of Iranian white cheese was assessed. The particle size, polydispersity index value (PDI), zeta potential, antioxidant activity, and encapsulation efficiency of the optimal chitosan-ZEO-nisin nanogel were 421.6 nm, 0.343, 34.0 mV, 71.06%-82.69%, and 41.3 ± 0.5%, 0.79 ± 0.06 mg/mL. respectively. FTIR and XRD approved ZEO and nisin entrapment within chitosan nanogel. The chitosan nanogel showed a highly porous surface with an irregular shape. The bioactive compounds of ZEO and nisin decreased the pH changes in cheese. On the 60th day of storage, the acidity of treated samples was significantly lower than that of control. Although the lowest anisidine index value was observed in samples treated with sodium nitrate (NaNO3) (TS), there was no significant difference between this sample and TCZN. The lowest microbial population was observed in TCZN and TS. After 60 days of ripening, Coliforms were not detected in the culture medium of TCZN and TS. The results can contribute to the development of a natural preservative with the potential for application in the dairy industry.

Smart chitosan nanogel for targeted doxorubicin delivery, ensuring precise release, and minimizing side effects in Ehrlich ascites carcinoma-bearing mice

In recent decades, bio-polymeric nanogels have become a forefront in medical research as innovative in-vivo drug carriers. This study introduces a pH-sensitive chitosan nanoparticles/P(N-Isopropylacrylamide-co-Acrylic acid) nanogel (CSNPs/P(NIPAm-co-AAc)), making significant advancements. The nanogel effectively encapsulated doxorubicin hydrochloride (Dx. HCl), a model drug, within its compartments through electrostatic binding. Comparing nano chitosan (CSNPs) before and after integrating copolymerized P(NIPAm-co-AAc), highlighting an improved and adaptable nanogel structure with responsive behaviors. The intraperitoneal delivery of Dx-loaded nanogel (Dx@N.gel) to Ehrlich ascites carcinoma (Eh)-bearing mice at doses equivalent to 1.5 and 3 mg/kg of Dx per day for 14 days exhibited superiority over the administration of free Dx. Dx@N.gel demonstrated heightened anticancer activity, significantly improving mean survival rates in Eh mice. The nanogel's multifaceted defense mechanism mitigated oxidative stress, inhibited lipid peroxidation, and curbed nitric oxide formation induced by free Dx. It effectively countered hepatic DNA deterioration, normalized elevated liver and cardiac enzyme levels, and ameliorated renal complications. This pH-responsive CSNPs/P(NIPAm-co-AAc) nanogel loaded with Dx represents a paradigm shift in antitumor drug delivery. Its efficacy and ability to minimize side effects, contrasting sharply with those of free Dx, offer a promising future where potent cancer therapies seamlessly align with patient well-being.

Trinitroglycerin-loaded chitosan nanogels: Shedding light on cytotoxicity, antioxidativity, and antibacterial activities

Aim and backgroundTrinitroglycerin (TNG) is a remarkable NO-releasing agent. Here, we synthesized TNG based on chitosan Nanogels (Ngs) for ameliorating complications associated with high-dose TNG administration. MethodTNG-Ngs fabricated through ionic-gelation technique. Fourier-transformed infrared (FT-IR), zeta-potential, dynamic light scattering (DLS), and electron microscopy techniques evaluated the physicochemical properties of TNG-Ngs. MTT was used to assess the biocompatibility of TNG-Ngs, as the antioxidative properties were determined via lactate dehydrogenase (LDH), reactive oxygen species (ROS), and lipid peroxide (LPO) assays. The antibacterial activity was evaluated against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococci (VRE). ResultsPhysicochemical characterization reveals that TNG-Ngs with size diameter (96.2 ± 29 nm), polydispersity index (PDI, 0.732), and negative zeta potential (−1.1 mv) were fabricated. The encapsulation efficacy (EE) and loading capacity (LC) were obtained at 71.1 % and 2.3 %, respectively, with no considerable effect on particle size and morphology. The cytotoxicity assay demonstrated that HepG2 cells exposed to TNG-Ngs showed relative cell viability (RCV) of >80 % for 70 μg/ml compared to the TNG-free drug at the same concentration (P < 0.05). TNG-Ngs showed significant differences with the TNG-free drug for LDH, LPO, and ROS formation at the same concentration (P < 0.001). The antibacterial activity of the TNG-Ngs against S. aureus, E. coli, VRE, and MRSA was higher than the TNG-free drug and Ngs (P < 0.05). ConclusionTNG-Ngs with enhanced antibacterial and antioxidative activity and no obvious cytotoxicity might be afforded as novel nanoformulation for promoting NO-dependent diseases.

ANTIMICROBIAL NANOGELS TO PREVENT ORTHOPAEDIC DEVICE-RELATED INFECTIONS

Orthopedic Device-Related Infections (ODRIs) are a major medical challenge, particularly due to the involvement of biofilm-encased and multidrug-resistant bacteria. Current treatments, based on antibiotic administration, have proven to be ineffective. Consequently, there is a need for antibiotic-free alternatives. Antimicrobial peptides (AMPs) are a promising solution due to their broad-spectrum of activity, high efficacy at very low concentrations, and low propensity to induce resistance. We aim to develop a new AMP-based chitosan nanogel to be injected during orthopedic device implantation to prevent ODRIs. Chitosan was functionalized with norbornenes (NorChit) through the reaction with carbic anhydride and then, a cysteine-modified AMP, Dhvar5, a peptide with potent antibacterial activity, even against methicillin-resistant Staphylococcus aureus (MRSA), was covalently conjugated to NorChit (NorChit- Dhvar5), through a thiol-norbornene photoclick chemistry (UV= 365 nm). For NorChit-Dhvar5 nanogels production, the NorChit-Dhvar5 solution (0.15% w/v) and Milli-Q water were injected separately into microfluidic system. The nanogels were characterized regarding size, concentration, and shape, using Transmission Electron Microscopy (TEM), Nanoparticle Tracking Analysis (NTA) and Dynamic light scattering (DLS). The nanogels antibacterial properties were assessed in Phosphate Buffer (PBS) for 6 h, against four relevant microorganisms (Pseudomonas aeruginosa, S. aureus and MRSA, and in Muller- Hinton Broth (MHB), 50% (v/v) in PBS, supplemented with human plasma (1% (v/v)), for 6 and 24 h against MRSA. The obtained NorChit-Dhvar5 nanogels, presented a round-shaped and ∼100 nm. NorChit- Dhvar5 nanogels in a concentration of 1010 nanogels/mL in PBS were capable of reducing the initial inoculum of P. aeruginosa by 99%, S. aureus by 99%, and MRSA by 90%. These results were corroborated by a 99% MRSA reduction, after 24 h in medium. Furthermore, NorChit-Dhvar5 nanogels do not demonstrate signs of cytotoxicity against MC3T3-E1 cells (a pre-osteoblast cell line) after 14 days, having high potential to prevent antibiotic-resistant infection in the context of ODRIs.

Chitosan nanogel aqueous treatment improved blood biochemicals, antioxidant capacity, immune response, immune-related gene expression and infection resistance of Nile tilapia.

Candida albicans is a pathogenic yeast recently associated with diverse diseases in aquaculture. The present study investigated the efficacy of chitosan nanogel (CNG) in ameliorating effects of C. albicans on Nile tilapia (Oreochromis niloticus). Fish were randomly distributed into four groups (control, waterborne CNG at 75μg/L, intraperitoneally challenged with C. albicans (1.8×107CFU/mL), and waterborne CNG at 75μg/L+C. albicans at 1.8×107CFU/mL). Results showed that C. albicans infection reduced survival rate (57.5%) and caused marked clinical symptoms in fish among all infected groups. Substantial declines in immunological (complement 3, lysozyme, and immunoglobulin M), protein (total protein and non-albumin protein), and antioxidant (catalase, glutathione peroxidase, and superoxide dismutase) biochemical endpoints were exhibited, The C. albicans infected group also showed marked down-regulation in the expression of immune-related genes, including toll-like receptor 2 (TLR-2), transforming growth factor beta2, tumor necrosis factor alpha, interleukins (IL-1β, IL-6, and IL-10), and antiapoptotic gene (B-cell lymphoma, BCL-2). The expression of the apoptotic gene (Bcl-2 associated X protein, BAX) was up-regulated in fish challenged by C. albicans. The application of waterborne CNG to fish challenged with C. albicans infection improved fish survival (79.5%) and all other measured parameters. The main finding of this work was that CNG is a nanotechnology with potential for preventing degraded health status by C. albicans infection in tilapia, and thus has promise as an intervention in aquaculture settings.

Effects of Apigenin and Apigenin- Loaded Nanogel on Induction of Apoptosis in Human Chronic Myeloid Leukemia Cells

Background: Diet plays an important role in cancer prevention. Apigenin, a flavonoid with thechemical formula C15H10O5, is abundantly present in vegetables. Vegetarian foods containing flavonoids are rich sources of bioactive compounds. Flavonoids have been utilized in herbal treatment. Nanogels are drug delivery systems based on polymers and are used in tissue engineering and for drug delivery. This study was conducted to compare the effects of apigenin and a nanodrug on the viability of the K562 cell line of chronic myeloid leukemia at different durations under laboratory conditions. Materials and Methods: Chitosan was first dissolved in 1% acetic acid, and ethylene dichloride EDC and NHS were added to the solution. Then, the nanodrug was prepared by loading apigenin into stearate–chitosan nanogel (scs nanogel), and its physical and morphological characteristics were evaluated by TEM, DLS, and FTIR. Trypan blue staining, MTT assay, and flow cytometry were used to analyze the effects of various concentrations of apigenin and apigenin-loaded chitosan–stearate nanogel (APG–SCS) at 24, 48, and 72 h after they were applied to the K562 cell line. Results: The diameter of the nanodrug particles was measured using DLS and confirmed by TEM. The K562 cells treated with APG–SCS and with apigenin exhibited significant differences compared with the control (P &lt; 0.05). Apoptosis was detected by flow cytometry. Conclusion: This study showed that the toxic effects of apigenin and the nanodrug improved with increasing concentrations and exposure durations compared to those in the control.The toxic effect of apigenin loaded into the stearate-chitosan nanogel was greater than apigenin, and the toxic effects of both materials were greater compared to the control under laboratory conditions.[GMJ.2018;7:e1008]

Effect of Immersion Duration in Coffee Beverage on Colour Stability of Polymethyl Methacrylate Denture Base Reinforced with 1% Chitosan Nanogel (Laboratory Study)

Hot polymerized acrylic resin (RAPP) denture bases have several weaknesses, so RAPP requires reinforcing materials, one of which is chitosan. Extrinsic factors cause color changes in RAPP. The aim of this research was to determine the effect of soaking time for RAPP denture base material after adding 1% chitosan nanogel in coffee solution on color stability. Laboratory experimental research, using 16 cylindrical plates, diameter 15 x 2 mm (n = 8 from each group). There are 2 groups, the water-soaked group and the coffee drink group. Color stability measurements were carried out before and after soaking for 1, 2, 3, 4, and 7 days. The color stability of the samples was tested using a colorimeter and color changes were analyzed using the Kruskall-Wallis and Mann-Withney tests. There is an effect of soaking time for RAPP denture base material on color stability with a value of p = 0.0001. Soaking the RAPP denture base material after adding 1% chitosan nanogel in a coffee solution for color stability for 4 days is still clinically acceptable.

Biomimetic Nanoarchitectonics with Chitosan Nanogels for Collaborative Induction of Ferroptosis and Anticancer Immunity for Cancer Therapy.

Immunogenic cell death (ICD) shows promising therapeutic potential for tumor regression. However, the low sensitivity and immunosuppressive state of current cell death manners seriously impede tumor immunogenicity. Ferroptosis characterized by excessive lipid peroxidation, has emerged as a potential strategy to induce ICD and activate antitumor immune responses. However, the effectiveness of ferroptosis is limited by antioxidant regulatory networks, including the glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1) pathways, presenting challenges for its induction. Herein, they propose a novel approach that involves utilizing functionalized chitosan-ferrocene-sodium alginate (CFA) crosslinked nanogels, which are modified to pravastatin (PRV) and M1 macrophage membrane (MM) (designing as CFA/PRV@MM). Specifically, ferrocene boots intracellular reactive oxygen species levels for efficient glutathione (GSH) depletion through Fenton reaction, thus disrupting the GPX4/GSH axis, while PRV intervenes in the mevalonate pathway to inhibit the FSP1/CoQ10 antioxidant axis, thereby synergistically causing pronounced ferroptotic damage and promoting ICD. The CFA/PRV@MM nanogels demonstrate superior therapeutic efficacy in a mouse breast model, resulting in effective tumor ablation and immune response with minimal side effects. RNA transcription analysis reveals that nanogels can significantly affect metabolic progress, as well as immune activation. This research provides valuable insights into the design of ferroptosis induction for cancer immunotherapy.

Sprayable chitosan nanogel with nitric oxide to accelerate diabetic wound healing through bacteria inhibition, biofilm eradication and macrophage polarization

Bacterial infection and chronic inflammation are two major risks in diabetic wound healing, which increase patient mortality. In this study, a multifunctional sprayable nanogel (Ag-G@CS) based on chitosan has been developed to synergistically inhibit bacterial infection, eradicate biofilm, and relieve inflammation of diabetic wounds. The nanogel is successfully crafted by encapsulating with a nitric oxide (NO) donor and performing in-situ reduction of silver nanoparticles (Ag). The released NO enhances the antibacterial efficacy of Ag, nearly achieving complete eradication of biofilms in vitro. Upon application on both normal or diabetic chronic wounds, the combination effects of released NO and Ag offer a notable antibacterial effect. Furthermore, after bacteria inhibition and biofilm eradication, the NO released by the nanogel orchestrates a transformation of M1 macrophages into M2 macrophages, significantly reducing tumor necrosis factor α (TNF-α) release and relieving inflammation. Remarkably, the released NO also promotes M2a to M2c macrophages, thereby facilitating tissue remodeling in chronic wounds. More importantly, it upregulates the expression of vascular endothelial growth factor (VEGF), further accelerating the wound healing process. Collectively, the formed sprayable nanogel exhibits excellent inhibition of bacterial infections and biofilms, and promotes chronic wound healing via inflammation resolution, which has excellent potential for clinical use in the future.

LC-MS based metabolic profiling and wound healing activity of a chitosan nanoparticle-loaded formula of Teucrium polium in diabetic rats

Healing of wounds is the most deteriorating diabetic experience. Felty germander (Teucrium polium) possesses antioxidant, anti-inflammatory and antimicrobial activities that could accelerate wound healing. Further, nanohydrogels help quicken healing and are ideal biomaterials for drug delivery. In the current study, the chemical profiling, and standardization of T. polium methanolic extract by LC-ESI/TOF/MS/MS and quantitative HPLC-DAD analyses were achieved. The wound healing enhancement in diabetic rats by T. polium nanopreparation (TP-NP) as chitosan nanogel (CS-NG) and investigating the potential mechanisms were investigated. The prepared hydrogel-based TP-NP were characterized with respect to particle size, zeta potential, pH, viscosity, and release of major components. LC-ESI/TOF/MS/MS metabolomic profiling of T. polium revealed the richness of the plant with phenolic compounds, particularly flavonoids. In addition, several terpenoids were detected. Kaempferol content of T. polium was estimated to be 7.85 ± 0.022 mg/ g of dry extract. The wound healing activity of TP-NP was explored in streptozotocin-induced diabetic rats. Diabetic animals were subjected to surgical wounding (1 cm diameter). Then they were divided in 5 groups (10 each). These included Group 1 (untreated control rats), Group 2 received the vehicle of CS-NG; Group 3 (0.5 g of TP prepared in hydrogel), Group 4 (0.5 g of TP-NP), Group 5 represented a positive control treated with 0.5 g of a commercial product. All treatments were applied topically for 21 days. Application of TP-NP on skin wounds of diabetic animals accelerated the healing process as evidenced by epithelium regeneration, formation of granulation tissue followed by epidermal proliferation, along with keratinization as verified by H&E. This was confirmed through enhanced collagen synthesis, as shown by raised hydroxyproline content and Col1A1 gene expression. Moreover, TP-NP significantly alleviated wound oxidative burst and diminished the expressions of inflammatory biomarkers. Meanwhile, TP-NP could enhance the expressions of transforming growth factor beta1 (TGF-β1), in addition to the angiogenic markers; vascular endothelia growth factor A (VEGFA) and platelet-derived growth factor receptor alpha (PDGFRα). Collectively, chitosan nanogel of T. polium accelerates wound healing in diabetic rats, which could be explained – at least partly – through alleviating oxidative stress and inflammation coupled with pro-angiogenic capabilities.

Reaction kinetics of chitosan nanogels crosslinked by genipin

Crosslinking of chitosan chains in dilute solution by natural crosslinker genipin leads to biocompatible nanogels. Here we investigated the reaction kinetics between chitosan and genipin in a 200 mM acetate buffer at 37 °C, and the structural and conformational evolutions of the nanogels during the crosslinking reaction by multi detection asymmetric flow field-flow fractionation (AF4). Upon crosslinking by genipin, the z-average hydrodynamic radius Rhz of the chitosan chains increased from 26 nm to 130 nm, while the weight average molar mass Mw increased from 2.0 × 105 g/mol to 1.8 × 107 g/mol. The crosslinking reaction appeared to be first-order and size-dependent. In particular, the intrachain crosslinking reaction was preferentially for nanogels having the larger size, leading to formation of branched chains/nanogels having a wide range of molar masses between 106 and 108 g/mol but a similar radius of gyration Rg ∼ 40 nm. For the largest nanogel fractions with M > 2.0 × 108 g/mol, both Rg and Rh showed a scaling relation with exponent 1/3 and a structure parameter Rg/Rh = 0.74, as expected for the hard sphere particle. The reaction was accompanied by a reduction of charge density and an increase in hydrophobicity of chitosan nanogels, which plays a key role in the formation of uniform size nanogels with chain density ρ(Rh) up to 0.45 g/cm3.

Mucosal Adhesive Chitosan Nanogel Formulations of Antibiotics and Adjuvants (Terpenoids, Flavonoids, etc.) and Their Potential for the Treatment of Infectious Diseases of the Gastrointestinal Tract.

Bacterial infections are usually found in the stomach and the first part of the small intestine in association with various pathologies, including ulcers, inflammatory diseases, and sometimes cancer. Treatment options may include combinations of antibiotics with proton pump inhibitors and anti-inflammatory drugs. However, all of them have high systemic exposure and, hence, unfavorable side effects, whereas their exposure in stomach mucus, the predominant location of the bacteria, is limited. Chitosan and nanogels based on chitosan presumably are not absorbed from the gastrointestinal tract and are known to adhere to the mucus. Therefore, they can serve as a basis for the local delivery of antibacterial drugs, increasing their exposure at the predominant location of therapeutic targets, thus improving the risk/benefit ratio. We have used E. coli ATCC 25922 (as a screening model of pathogenic bacteria) and Lactobacilli (as a model of a normal microbiome) to study the antibacterial activity of antibacterial drugs entrapped in a chitosan nanogel. Classical antibiotics were studied in a monotherapeutic regimen as well as in combination with individual terpenoids and flavonoids as adjuvants. It has been shown that levofloxacin (LF) in combination with zephirol demonstrate synergistic effects against E. coli (cell viability decreased by about 50%) and, surprisingly, a much weaker effect against Lactobacilli. A number of other combinations of antibiotic + adjuvant were also shown to be effective. Using FTIR and UV spectroscopy, it has been confirmed that chitosan nanogels with the drug are well adsorbed on the mucosal model, providing prolonged release at the target location. Using an ABTS assay, the antioxidant properties of flavonoids and other drugs are shown, which are potentially necessary to minimize the harmful effects of toxins and radicals produced by pathogens. In vivo experiments (on sturgeon fish) showed the effective action of antibacterial formulations developed based on LF in chitosan nanogels for up to 11 days. Thus, chitosan nanogels loaded with a combination of drugs and adjuvants can be considered as a new strategy for the treatment of infectious diseases of the gastrointestinal tract.