Colonic long-term retention and colonization of probiotics by double-layer chitosan/tannic acid coating and microsphere embedding for treatment of ulcerative colitis and radiation enteritis.

Oral probiotics can alleviate enteric inflammations but their rapid transit through the gut limits their retention and colonization in the colon. Here, a novel strategy integrating the bacterial double-layer coating and hydrogel microsphere embedding techniques was used to highly enhance the colonic retention and colonization efficiency of Lactobacillus rhamnosus GG (LGG). LGG was coated by the double layers of chitosan (CS) and tannic acid (TA), and then embedded in calcium alginate (CA) hydrogel microspheres to form LGG@CT@CA. The microspheres resisted gastric liquids, improving LGG safe transit through the stomach to reach the colon. LGG@CT was rapidly released in the colon due to the good swelling of hydrogel microspheres. More importantly, LGG exhibited long-term retention up to 7 days in the colon and colonized the deep site of the colonic mucosa. LGG@CT@CA had a high therapeutic efficiency of ulcer colitis with the long colon and the low intestinal permeability of colonic tissues. LGG@CT@CA also alleviated the small intestinal damage induced by irradiation and the survival rates were improved. The mechanisms included local ROS decrease, IL-10 increase, and ferroptosis reduction in the small intestine. The oral colon-targeted system holds promise for oral probiotic therapy by the long-term retention and colonization in the colon.

Smear layer removal and antimicrobial efficacy of chitosan as a root canal irrigant: a systematic review of in-vitro studies.

This systematic review was designed to answer the following question: Does chitosan provide better smear layer removal and antimicrobial efficacy than other root canal irrigants? A literature search was done using electronic databases PubMed, Scopus, Web of Science, Cochrane Library, EBSCO host, Grey Literature Report, and Open Grey from inception to June 18, 2024. The reference lists of included articles were also hand-searched. Two reviewers independently assessed the studies' eligibility based on the inclusion and exclusion criteria and performed data extraction. Two reviewers independently evaluated the risk of bias in the selected studies. The search retrieved 2330 studies. After analysis, 36 studies fulfilled the eligibility criteria and were included, with 19 involving smear layer removal, 16 involving antibacterial efficacy, and 1 involving both. The overall risk of bias of the included studies was medium. Chitosan removed the smear layer more effectively than citric acid and acetic acid, similar to MTAD and Qmix, with conflicting results against EDTA. In addition, chitosan demonstrated comparable antibacterial efficacy to chlorhexidine, propolis, and photodynamic therapy but was less effective than sodium hypochlorite. Based on available evidence, it was found that chitosan provided better smear layer removal and antimicrobial efficacy than most root canal irrigants compared in this systematic review. There was substantial heterogeneity in the methodology of included studies. As a result, this review highly recommends further research using standardized methods to assess the effectiveness of chitosan as a root canal irrigant in in-vitro studies to validate its clinical use.

Chitosan-based smart stimuli-responsive nanoparticles for gene delivery and gene therapy: Recent progresses on cancer therapy.

Recent cancer therapy research has found that chitosan (Ch)-based nanoparticles show great potential for targeted gene delivery. Chitosan, a biocompatible and biodegradable polymer, has exceptional properties, making it an ideal carrier for therapeutic genes. These nanoparticles can respond to specific stimuli like pH, temperature, and enzymes, enabling precise delivery and regulated release of genes. In cancer therapy, these nanoparticles have proven effective in delivering genes to tumor cells, slowing tumor growth. Adjusting the nanoparticle's surface, encapsulating protective agents, and using targeting ligands have also improved gene delivery efficiency. Smart nanoparticles based on chitosan have shown promise in improving outcomes by selectively releasing genes in response to tumor conditions, enhancing targeted delivery, and reducing off-target effects. Additionally, targeting ligands on the nanoparticles' surface increases uptake and effectiveness. Although further investigation is needed to optimize the structure and composition of these nanoparticles and assess their long-term safety, these advancements pave the way for innovative gene-focused cancer therapies.

Development and optimization of electrosprayed vitamin C - chitosan nanoparticle: A CCD-RSM approach and characterization of bioactive encapsulant.

Electrospraying for Vitamin C (VC) encapsulation in Chitosan (Cs) nanoparticles was investigated and particle size, zeta potential, loading capacity (LC%) and encapsulation efficiency (EE%) were examined. Cs concentration (1-2% w/v) and voltage (21-25 kV) were varied with VC (0.25-0.75 w/w Cs). Twenty experiments in a face-centered CCD-RSM design were evaluated. ANOVA suggested voltage and Cs concentration as significant factors for particle size and VC content affected zeta, LC and EE%. RSM proposed optimum processing parameter at 2% Cs, 0.746 VC: Cs mass ratio and 21 kV voltage with 251.1 ± 59.03 nm particle size, 36.6% LC and an EE of 85.42%. Encapsulated particles were subjected to release behaviour, antioxidant property and analyzed through FTIR, DSC and XRD. Encapsulated VC had better antibacterial properties than Cs nanoparticles, and comparable VC retention in apple juice showed its effectiveness. Overall, nanoencapsulation of VC using electrospraying was successfully developed to be used in numerous food processing applications.

Chitosan: A Versatile Biomaterial Revolutionizing Endodontic Therapy.

Owing to their nanoscale dimensions, nanomaterials have special chemical and physical properties that set them apart from their bulk counterparts. The exterior dimensions of a minimum of half of the particles span several nanometers in their size distribution. Silver nanoparticles (AgNPs) are one type of nanomaterial that has been widely used because of their strong antibacterial properties, which can kill bacteria that are resistant to many drugs. Due to its potential for regulated release, localized retention, and safeguarding the active ingredients against environmental or enzymatic deterioration, nanoparticle technology has also emerged as a promising medication delivery method. The techniques for creating nanoparticles can be easily scaled up and used for a wide variety of medications. Since polymeric nanoparticles are biodegradable, biocompatible, and have more readily available formulation techniques than other nanoparticle drug delivery approaches, their range of applications has been expanding. Chitosan, also known as deacetylated polysaccharide, is a straight-chain cationic polymer that is typically a cationic copolymer. It can be generated naturally or by deacetylating chitin. Consequently, it contains an extensive array of biomedical applications, such as efficient healing of wounds, regeneration of tissues, regeneration of bone, and anti-infection. Because of its functional diversity, accessibility, and being both biodegradable and biocompatible, it has a wide spectrum of uses in dentistry. Recent research on chitosan-based nanoparticles is founded on the field's growing comprehension of the characteristics of chitosan and techniques for chemical or physical modification that are used to optimize the drug loading and release characteristics of the nanoparticles.

Synthesis of chitosan polyethylene glycol antibody complex for delivery of Imatinib in lung cancer cell lines.

Lung cancer is known as the most common cancer. Although the Ramucirumab antibody is a second-line treatment for lung cancer, the high interstitial fluid pressure limits the antibody's performance. In this way, Imatinib is a chemotherapeutic drug to reduce the interstitial fluid pressure. Up to now, unfortunately, both Ramucirumab and imatinib have not been reported in one nanosystem for cancer therapy. To fulfill this shortcoming, this paper aims to design a chitosan nanocarrier that loads imatinib and attaches to Ramucirumab for selective bonding to A549. Therefore, this paper aims to develop a polymeric nanosystem for non-small cell lung cancer (NSCLC) treatment. In first, the chitosan polyethylene glycol nanoparticle is synthesized, loaded with imatinib, and then targeted using Ramucirumab. Afterwards, the CS-PEG-Ab-Im by FTIR, TEM, DLS, zeta potential, and TGA techniques are characterized. The size of CS-PEG-Ab-Im was 25-30 nm, its surface charge was 13.1 mV, and the shape of CS-PEG-Ab-Im was nearly spherical and cylindrical. The therapeutic potential of CS-PEG-Ab-Im was assessed using the A549 cell line. According to the obtained results, the cell viability was 48% after 48 h of treatment of A549 cells using the IC50 concentration of CS-PEG-Ab-Im (100 nanomolar). Moreover, the apoptosis and cell cycle arrest percentages were increased by 3 and 6 times, respectively, as compared to free imatinib. Furthermore, the release rate of imatinib from CS-PEG-Ab-Im in an acidic medium was 17% during 1 h, indicating five times the imatinib release in the natural medium. Eventually, the result of flow cytometry indicates the more apoptotic effect of nanosystem to free imatinib and CS-PEG-Ab. Besides, cell arresting result exhibits the CS-PEG-Ab-Im and causes cell arrested at G1 by %8.17. Thus, it can be concluded that CS-PEG-Ab-Im can be an ideal nanosystem in NSCLC treatment.

Development of transgenic Paulownia trees expressing antimicrobial thionin genes for enhanced resistance to fungal infections using chitosan nanoparticles.

There is an increasing focus on genetically altering Paulownia trees to enhance their resistance against fungal infections, given their rapid growth and quality wood production. The aim of this research was to establish a technique for incorporating two antimicrobial thionin genes, namely thionin-60 (thio-60) and thionin-63 (thio-63), into Paulownia tomentosa and Paulownia hybrid 9501 through the utilization of chitosan nanoparticles. The outcomes revealed the successful gene transfer into Paulownia trees utilizing chitosan nanoparticles. The effectiveness of thionin proteins against plant pathogens Fusarium and Aspergillus was examined, with a specific focus on Fusarium equiseti due to limited available data. In non-transgenic Paulownia species, the leaf weight inhibition percentage varied from 25 to 36 %, whereas in transgenic species, it ranged from 22 to 7 %. In general, Paulownia species expressing thio-60 displayed increased resistance to F. equiseti, while those expressing thio-63 exhibited heightened resistance to A. niger infection. The thionin proteins displayed a strong affinity for the phospholipid bilayer of the fungal cell membrane, demonstrating their capability to disrupt its structure. The transgenic plants created through this technique showed increased resistance to fungal infections. Thionin-60 demonstrated superior antifungal properties in comparison to thio-63, being more effective at disturbing the fungal cell membrane. These findings indicate that thio-60 holds potential as a novel antifungal agent and presents a promising approach for enhancing the antimicrobial traits of genetically modified Paulownia trees.

Microfluidic Synthesis of Scalable Layer-by-Layer Multiple Antigen Nano-Delivery Platform for SARS-CoV-2 Vaccines.

The COVID-19 outbreak was a global pandemic with wide-ranging healthcare implications. Although several mRNA-based vaccines delivered using lipid nanoparticles (LNP) have been approved and demonstrated efficacy at reducing the severity and spread of infection, continued rapid viral evolution and disadvantages currently associated with LNP delivery vehicles (such as toxicity) are driving the design of next-generation SARS-CoV-2 vaccines. Herein, we describe the development of a trimethylated chitosan-based nanoparticle layer-by-layer (LbL) delivery platform for multiple antigens as a scalable and safe COVID-19 vaccine, known as, "LbL-CoV19". These vaccine candidates have been demonstrated to be biocompatible, safe, and effective at stimulating both humoral and cellular responses for protection in preclinical studies. Preliminary results also indicate that LbL-CoV19 can potentially achieve rapid, long-lasting, and broad protection against the SARS-CoV-2 challenge. The "plug-and-play" platform technology is well suited to preparedness for future pandemics and disease outbreaks.

Chitosan-nanoparticle-based oral Salmonella enteritidis subunit vaccine elicits cross-protection against Salmonella typhimurium in broilers.

Non-typhoidal Salmonella infection is a significant health and economic burden in poultry industry. Developing an oral vaccine to induce robust mucosal immunity in the intestines of birds, especially cross protection against different Salmonella serotypes is challenging. Therefore, a potent oral vaccine platform that can mitigate different serotypes of Salmonella is warranted for the poultry industry. We reported earlier that the Salmonella enteritidis (SE) immunogenic outer membrane proteins (OMPs) and flagellin (FLA) entrapped in mannose chitosan nanoparticles (OMPs-FLA-mCS NPs) administered prime-boost (d-3 and 3-wk later) by oral inoculation elicits mucosal immunity and reduces challenge SE colonization by over 1 log10 CFU in birds. In this study, we sought to evaluate whether the SE antigens containing OMPs-FLA-mCS NPs vaccine induces cross-protection against Salmonella typhimurium (ST) in broilers. Our data indicated that the OMPs-FLA-mCS NPs vaccine induced higher cross-protective antibody responses compared to commercial Poulvac ST vaccine (contains a modified-live ST bacterium). Particularly, OMPs-FLA-mCS-NP vaccine elicited OMPs and FLA antigens specific increased production of secretory IgA and IgY antibodies in samples collected at both post-vaccination and post-challenge timepoints compared to commercial vaccine group. Notably, the vaccine reduced the challenge ST bacterial load by 0.8 log10 CFU in the cecal content, which was comparable to the outcome of Poulvac ST vaccination. In conclusion, our data suggested that orally administered OMPs-FLA-mCS-NP SE vaccine elicited cross protective mucosal immune responses against ST colonization in broilers. Thus, this candidate vaccine could be a viable option replacing the existing both live and killed Salmonella vaccines for birds.

Quality by design (QbD) approach-based development of optimized nanocarrier to achieve quality target product profile (QTPP)-targeted lymphatic delivery.

Background.Insulin, commonly used for diabetes treatment, needs better ways to improve its effectiveness and safety due to its challenges with poor permeability and stability. Various system has been developed for oral peptide delivery. The non-targeted system can prevent gastric and enzymatic degradation of peptides but cannot increase the bulk transport of peptides across the membrane. However, the non-selectivity is the limitation of the existing system. Numerous carbohydrate-binding receptors overexpressed on intestinal macrophage cells (M-cells) of gut-associated lymphoid tissue. It is the most desirable site for receptor-mediated endocytosis and lymphatic drug delivery of peptides.Objective. The prime objective of the study was to fabricate mannose ligand conjugated nanoparticles (MNPs) employing a quality-by-design approach to address permeability challenges after oral administration. Herein, the study's secondary objective of this study is to identify the influencing factor for producing quality products. Considering this objective, the Lymphatic uptake of NPs was selected as a quality target product profile (QTPP), and a systematic study was conducted to identify the critical formulation attributes (CFAs) and critical process parameters (CPP) influencing critical quality attributes (CQAs). Mannosylated Chitosan concentrations (MCs) and TPP concentrations were identified as CFAs, and stirring speed was identified as CPP.Methods. MNPs were prepared by the inotropic gelation method and filled into the enteric-coated capsule to protect from acidic environments. The effect of CFAs and CPP on responses like particle size (X) and entrapment (Y) was observed by Box-Behnken design (BBD). ANOVA statistically evaluated the result to confirm a significant level (p< 0.05). The optimal conditions of NPs were obtained by constructing an overlay plot and determining the desirability value. HPLC and zeta-seizer analysis characterized the lyophilized NPs. Cell-line studies were performed to confirm the safety and M-cell targeting of NPs to enhance Insulin oral bioavailability.Results. The morphology of NPs was revealed by SEM. The developed NPs showed a nearly oval shape with the average size, surface potential, and % drug entrapment were 245.52 ± 3.37 nm, 22.12 ± 2.13 mV, and 76.15 ± 1.3%, respectively. MTT assay result exhibited that MNPs safe and Confocal imaging inference that NPs selectively uptake by the M-cell.Conclusion. BBD experimental design enables the effective formulation of optimized NPs. The statistical analysis estimated a clear assessment of the significance of the process and formulation variable. Cell line study confirms that NPs are safe and effectively uptake by the cell.

In vitro and functional investigation reveals the curative effect of thymoquinone from black cumin-loaded chitosan nanoparticles on streptozotocin induced paediatric diabetes.

Diabetic ketoacidosis (DKA) is regarded to be a communal complication of both type 1 and type 2 diabetes mellitus in children and adolescents. Successful therapy of DKA in children requires prompt diagnosis, strict monitoring of medical indicators, and prompt action. Thymoquinone (Tq) from black cumin loaded chitosan nanoparticles (ChNPs) intend to assess an effective agent to overcome this problem. XRD, FTIR, SEM, and TEM were used in the physicochemical analysis. Enzymatic activity of α-amylase and α-glucosidase was used in in vitro tests of anti-diabetic efficacy. Protecting insulin against enzyme breakdown is a crucial part of the insulin delivery mechanism. In the STZ-induced diabetes RIN-5F cell line, the anti-apoptotic capability of Tq-ChNPs was demonstrated through the NF-κB mediated apoptotic pathway. The combination of thymoquinone and chitosan NPs demonstrated that a wide variety of incredibly effective substances to elevate their curative effects, thus contributing to the growth of clinical and pharmaceutical fields.

The effect of the enzymes trypsin and DNase I on the antimicrobial efficiency of root canal irrigation solutions.

The purpose of this study was to evaluate the antibacterial efficacy of using 2.5% NaOCl, 2% chlorhexidine (CHX), Irritrol, and chitosan-coated silver nanoparticles (AgCNPs) alone or in combination with deoxyribonuclease I (DNase I) and trypsin pre-enzyme applications in dentin samples contaminated with Enterococcus faecalis (E. faecalis) by CLSM. 144 dentin blocks with confirmed E. faecalis biofilm formation were divided randomly according to the irrigation protocol (n = 12): NaOCl, CHX, Irritrol, AgCNPs, trypsin before NaOCl, CHX, Irritrol, AgCNPs, and DNase I before NaOCl, CHX, Irritrol, AgCNPs. Dentin blocks were stained with the Live/Dead BacLight Bacterial Viability Kit and viewed with CLSM after irrigation applications. The percentage of dead and viable bacteria was calculated using ImageJ software on CLSM images. At a significance level of p < 0.05, the obtained data were analyzed using one-way Anova and post-hoc Tukey tests. In comparison with NaOCl, CHX had a higher percentage of dead bacteria, both when no pre-enzyme was applied and when DNase I was applied as a pre-enzyme (p < 0.05). There was no difference in the percentage of dead bacteria between the irrigation solutions when trypsin was applied as a pre-enzyme (p > 0.05). AgCNPs showed a higher percentage of dead bacteria when trypsin was applied as a pre-enzyme compared to other irrigation solutions (p < 0.05), while the pre-enzyme application did not affect the percentage of dead bacteria in NaOCl, CHX, and Irritrol (p > 0.05). No irrigation protocol tested was able to eliminate the E. faecalis biofilm. While the application of trypsin as a pre-enzyme improved the antimicrobial effect of AgCNPs, it did not make any difference over other irrigation solutions.

In vitro and In vivo Effects of Ethanolic Extract of Fumaria parviflora Lam. Embedded in Chitosan Nanoparticles Against Leishmania major.

INTRODUCTION: Fumaria has been traditionally used to treat skin damages due to anti-inflammatory properties. In the present study, we evaluated the effect of the ethanolic extract of Fumaria parviflora Lam. (F. parviflora) against Leishmania major (L. major) using chitosan biopolymer drug delivery system both In vitro and In vivo models. MATERIALS AND METHODS: The ethanolic extract of F. parviflora was analyzed by HPLC to determine its active ingredients content. The extract was then loaded on chitosan nanoparticles (CNPs). The parasite was treated with various concentrations of the ethanolic extract, CNPs and CNPs loaded with F. parviflora extract (CNPs@ F. parviflora). The size of lesions of treated mice were measured on a weekly basis. The parasite burden was evaluated 8 weeks after treatment. RESULTS: The HPLC analysis showed the presence of Fumaric acid at a high concentration. The percentage of the drug released from CNPs@ F. parviflora within 24 and 72 h were 65% and 90% respectively. The results showed that F. parviflora extract and CNPs@ F. parviflora caused 84% and 96% growth inhibition of L. major promastigotes as revealed by Neubauer chamber counting and MTT test respectively. The IC50 values of F. parviflora extract and CNPs@ F. parviflora were 450 and 68.4 µg/ml respectively. In amastigote assay, the best results showed in CNPs@ F. parviflora that only 2% of macrophages were infected with amastigotes. In vivo experiments for mice treated with F. parviflora and CNPs @ F. parviflora in comparison to control group showed a significant reduction (P < 0.05) in the mean diameter of the lesions (2.3 and 1.72 mm and 9.91 mm respectively). CONCLUSION: The ethanolic extract of F. parviflora both as standalone and loaded in CNPs showed promising inhibitory effects against L. major both upon In vitro and In vivo experimentation as well as therapeutic effects for wound healing in infected mice.

Starch biopolymer films containing chitosan nanoparticles: A review.

Starch biopolymer films incorporated with chitosan nanoparticles (CNP) or starch/CNP films are promising alternatives to non-degradable food packaging materials. The films can be utilized for active food packaging applications because CNP exhibits antimicrobial and antioxidant properties, which can improve food shelf-life. Nonetheless, knowledge of the effects of CNP inclusion on the properties of starch films is not fully elucidated. This paper reviews the influences of various concentrations of CNP, sizes of CNP, and other additives on the mechanical, thermal, barrier, antimicrobial, antioxidant, biodegradability, and cytotoxicity properties of starch/CNP films as well as the mechanisms involved in relation to food packaging applications. The usage of starch/CNP films for active food packaging can help to reduce environmental issues and contribute to food safety and security.

Effect of final irrigation protocols with chitosan nanoparticle and genipin on dentine against collagenase degradation: An ex-vivo study.

AIM: Endodontic irrigants may affect the mechanical and chemical properties of dentine. This study evaluated the effects of various final irrigation protocols including the use of chitosan nanoparticle (CSnp) and cross-linking with genipin on the (1) mechanical and (2) chemical properties of dentine against enzymatic degradation. METHODOLOGY: CSnp was synthesized and characterized considering physiochemical parameters and stability. The root canals of 90 single-rooted teeth were prepared and irrigated with NaOCl. Dentine discs were obtained and divided into groups according to the following irrigation protocols: Group NaOCl+EDTA, Group NaOCl+CSnp, Group NaOCl+EDTA+CSnp, Group NaOCl+CSnp+Genipin, Group NaOCl+EDTA+CSnp+Genipin and Group distilled water. (1) Mechanical changes were determined by microhardness analysis using Vickers-tester. (2) Chemical changes were determined by evaluating molecular and elemental compositions of dentine using Fourier transform infrared spectroscopy (FTIR) analysis and scanning electron microscope (SEM)/energy dispersive X-ray spectroscopy (EDS) analysis, respectively. All analyses were repeated after the discs were kept in collagenase for 24 h. Data were analysed with repeated measures analysis of variance and Bonferroni correction for microhardness analysis, and Kruskal-Wallis and Wilcoxon tests for FTIR and SEM/EDS analyses (p = .05). RESULTS: (1) Collagenase application did not have a negative effect on microhardness only in Group NaOCl+EDTA+CSnp+Genipin when compared with the post-irrigation values (p > .05). Post-collagenase microhardness of Group NaOCl+EDTA+CSnp and Group NaOCl+CSnp+Genipin was similar to the initial microhardness (p > .05). (2) After collagenase, Amide III/ PO 4 3 - ratio presented no change in Group NaOCl+EDTA+CSnp, Group NaOCl+CSnp+Genipin and Group NaOCl+EDTA+CSnp+Genipin (p > .05), while decreased in other groups (p < .05). Collagenase did not affect CO 3 2 - / PO 4 3 - ratio in the groups (p > .05). There were no changes in the groups in terms of elemental level before and after collagenase application (p > .05). CONCLUSIONS: CSnp and genipin positively affected the microhardness and molecular composition of dentine. This effect was more pronounced when CSnp was used after EDTA.

Therapeutic effect of 5-ASA and hesperidin-loaded chitosan/Eudragit® S100 nanoparticles as a pH-sensitive carrier for local targeted drug delivery in a rat model of ulcerative colitis.

Ulcerative colitis (UC) is an idiopathic disease characterized by colonic mucosal tissue destruction secondary to an excessive immune response. We synthesized pH-sensitive cross-linked chitosan/Eudragit® S100 nanoparticles (EU S100/CS NPs) as carriers for 5-aminosalicylic acid (5-ASA) and hesperidin (HSP), then conducted in-vitro and in-vivo studies and evaluated the therapeutic effects. In-vitro analysis revealed that the 5-ASA-loaded EU S100/CS NPs and the HSP-loaded EU S100/CS NPs had smooth and curved surfaces and ranged in size between 250 and 300 nm, with a zeta potential of 32 to 34 mV. FTIR analysis demonstrated that the drugs were loaded on the nanoparticles without significant alterations. The loading capacity and encapsulation efficiency of loading 5-ASA onto EU S100/CS NPs were 25.13 % and 60.81 %, respectively. Regarding HSP, these values were 38.34 % and 77.84 %, respectively. Drug release did not occur in simulated gastric fluid (SGF), while a slow-release pattern was recorded for both drugs in simulated intestinal fluid (SIF). In-vivo macroscopic and histopathological examinations revealed that both NPs containing drugs significantly relieved the symptoms of acetic acid (AA)-induced UC in Wistar rats. We conclude that the synthesized pH-sensitive 5-ASA/EU S100/CS NPs and HSP/EU S100/CS NPs offer promise in treating UC.

Preparation and characterization of 3D bioprinted gelatin methacrylate hydrogel incorporated with curcumin loaded chitosan nanoparticles for in vivo wound healing application.

This study developed a biomimetic composite bioink consisting of gelatin methacrylate (GelMA) /chitosan nanoparticles (CSNPs) for extrusion-based 3D bioprinting. Additionally, curcumin(Cur)-loaded nanoparticles were incorporated which increased the proliferation and antibacterial activity of biomimetic skin constructs. The hydrogel, curcumin-loaded NPs, and the biocomposite was characterized chemically and physically. The results indicated proper modified gelatin with tunable physical characteristics, e.g., swelling ratio and biodegradability up to 1200 % and 25 days, respectively. In addition, the characterized CSNPs showed good distribution with a size of 370 nm and a zeta potential of 41.1 mV. We investigated the mechanical and cytocompatibility properties of chitosan nanoparticles encapsulated in hydrogel for emulating an extracellular matrix suitable for skin tissue engineering. CSNPs entrapped in GelMA (15 % w/v) exhibited controlled drug release during 5 days, which was fitted into various kinetic models to study the mass transfer mechanism behavior. Also, the composite hydrogels were effective as a barrier against both gram-positive and gram-negative bacteria at a concentration of 50 µg/ml nanoparticles in GelMA 15 %. Furthermore, the biocomposite was applied on Wistar rats for wound healing. As a result, this study provides a GelMA-NP50-Cur3 scaffold that promotes cell proliferation and decreases microbial infections in wounds.

The comparative of chitosan and chitosan nanoparticle versus ethylenediaminetetraacetic acid on the smear layer removal: A systematic review and meta-analysis of in vitro study.

The purpose of this systematic review of meta-analysis was to compare the effectiveness of removing the smearing layer using EDTA versus Chitosan (Ch) and Chitosan nanoparticles (Ch-NPs). A search was performed in four electronic databases (Web of Science, PubMed, Scopus, and Cochrane). The included studies were assessed by two reviewers using Joanna Briggs Institute's critical appraisal checklist for the quasi-experimental studies. Outcomes obtained by scanning electron microscopy (SEM) and conventional methods were presented as standardized mean differences alongside 95% confidence intervals. Seven investigations employed 212 single-root teeth. In the apical section (p = .317, 95% CI = -0.820 to 0.266, Tau2 = 0.387), middle segment (p = .914, 95% CI = -1.019 to 0.912, Tau2 = 1.027), and coronal segment (p = .277, 95% CI = -1.008 to 0.289, Tau2 = 0.378). This meta-analysis found no difference between Ch, Ch-NPs, and EDTA in removing the smear layer in the three segments. This systematic review is designed to show evidence related to the PICO question, in which our outcome is smear layer removal and not the clinical success of such a treatment. RESEARCH HIGHLIGHTS: The study aimed to compare the effectiveness of chitosan and chitosan nanoparticles with ethylenediaminetetraacetic acid (EDTA) in removing the smear layer, a layer of debris and organic material on the tooth surface, through a systematic review and meta-analysis. The removal of the smear layer is crucial for successful dental treatments, as it enhances the adhesion of restorative materials and improves the penetration of antimicrobial agents into dentinal tubules. The researchers conducted a systematic review and meta-analysis, searching various databases of electron microscopy results for relevant in vitro studies comparing the effects of chitosan or chitosan nanoparticles with EDTA on smear layer removal. The results encourage further exploration of chitosan and chitosan nanoparticles for clinical use in dentistry, while considering their specific applications and long-term effects.

Novel Chimeric Endolysin Conjugated Chitosan Nanocomplex as a Potential Inhibitor Against Gram-Positive and Gram-Negative Bacteria.

Resistance to antimicrobial agents has created potential problems in finding efficient treatments against bacteria. Thus, using new therapeutics, such as recombinant chimeric endolysin, would be more beneficial for eliminating resistant bacteria. The treatment ability of these therapeutics can be further improved if they are used with biocompatible nanoparticles like chitosan (CS). In this work, covalently conjugated chimeric endolysin to CS nanoparticles (C) and non-covalently entrapped endolysin in CS nanoparticles (NC) were effectively developed and, consequently, qualified and quantified using analytical devices, including FT-IR, dynamic light scattering, and TEM. Eighty to 150 nm and 100 nm to 200 nm in diameter were measured for CS-endolysin (NC) and CS-endolysin (C) using a TEM, respectively. The lytic activity, synergistic interaction, and biofilm reduction potency of nano-complexes were investigated on Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa) strains. The outputs revealed a good lytic activity of nano-complexes after 24 h and 48 h of treatment, especially in P. aeruginosa (approximately 40% cell viability after 48 h of treatment with 8 ng/mL), and potential biofilm reduction performance was attained in E. coli strains (about 70% reduction after treatment with 8 ng/mL). The synergistic interaction between nano-complexes and vancomycin was exhibited in E. coli, P. aeruginosa, and S. aureus strains at 8 ng/mL concentrations, while the synergistic effects of pure endolysin and vancomycin were not remarkable in E. coli strains. These nano-complexes would be more beneficial in suppressing the bacteria with a high level of antibiotic resistance.

Efficacy of using chitosan and chitosan nanoparticles as final irrigating solutions on smear layer removal and mineral content of intraradicular dentin.

Background: This study evaluated the effect of using chitosan, nano-chitosan, and ethylenediaminetetraacetic acid (EDTA) as final irrigating solutions on smear layer cleanliness and Ca/P ratio of dentin. Methodology: Forty-eight decoronated human single-rooted teeth were used. They were divided randomly into four groups (n = 12) based on the final irrigating solution used as follows: (a) control group (IA; n = 6) normal saline, (IB; n = 6) were left unprepared; group II - 0.2% chitosan; group III - 0.2% nano-chitosan; and group IV - 17% EDTA. Samples were prepared using ProTaper Next and irrigated with 2.6% NaOCl 5 ml after each instrument using 31-gauge needle. Final rinse was used 5 ml/3 min according to the assigned group. The specimens were prepared for evaluation. Results: Best smear layer removal was observed in group IV. No statistically significant differences (P > 0.05) were observed between the experimental groups (II, III, and IV) coronally; however, a statistically significant difference (P < 0.05) was observed between groups II and IV at middle and apical thirds. Intragroup comparison showed that apical third exhibited the highest mean smear layer score among all experimental groups. The highest mean Ca/P ratio was in the 0.2% nano-chitosan group, while the highest calcium loss was in the 17% EDTA group. Conclusions: 17% EDTA is a potent chelating agent that can successfully remove the smear layer but compromises the Ca/p ratio of dentin. However, 0.2% chitosan and its nanoparticles have comparable chelating effects and induce remineralization of the root canal dentin.