Chitosan-curcumin complexation to develop functionalized nanosystems with enhanced antimicrobial activity against hetero-resistant gastric pathogen

Multifunctional curcumin-based polymer coating: A promising platform against bacteria, inflammation and coagulation

The extensive use of polymers in the medical field has facilitated the development of various devices and implants, contributing to the restoration of organ function. However, despite their advantages such as biocompatibility and robustness, these materials often face challenges like bacterial contamination and subsequent inflammation, leading to implant-associated infections (IAI). Integrating implants effectively is crucial to prevent bacterial colonization and reduce inflammatory responses. To overcome these major issues, surface chemical modifications have been extensively explored. Indeed, click chemistry, and particularly, copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction has emerged as a promising approach for surface functionalization without affecting material bulk properties. Curcumin, known for its diverse biological activities, suffers from low solubility and stability. To enhance its bioavailability, bioconjugation strategy has garnered attention in recent years. This study represents pioneering work in immobilizing curcumin derivative onto polyethylene terephthalate (PET) surfaces, aiming to combat bacterial adhesion, inflammation and coagulation. Before curcumin derivative bioconjugation, a fluorophore, dansyl derivative, was employed in order to monitor and determine the efficiency of the proposed methodology. Previous surface chemical modifications were required for the immobilization of both dansyl and curcumin derivatives. Ultraviolet-Visible (UV-Vis) demonstrated the amidation functionalization of PET surface. Other surface characterization techniques including X-ray Photoelectron Spectroscopy (XPS), Attenuated Total Reflectance Fourier Transformed Infrared (ATR-FTIR), Scanning Electron Microscopy (SEM) and contact angle, among others, confirmed also the conjugation of both dansyl and curcumin derivatives. On the other hand, different biological assays corroborated that curcumin derivative immobilized PET surfaces do not exhibit cytotoxicity effect. Additionally, corresponding inflammation test were performed, indicating that these polymeric surfaces do not produce inflammation and, when curcumin derivative is immobilized, they decrease the inflammation marker level (IL-6). Moreover, the bacterial growth of both Gram positive and Gram negative bacteria were measured, demonstrating that the immobilization of curcumin derivative on PET provided antibacterial properties to the material. Finally, hemolysis rate analysis and whole blood clotting assay demonstrated the antithrombogenic effect of PET-Cur surfaces as well as no hemolysis concern in the fabricated functional surfaces.

Turmeric and curcumin as adjuncts in controlling Helicobacter pylori-associated diseases: a narrative review

Non-antibiotic adjuncts may improve Helicobacter pylori infection control. Our aim was to emphasize curcumin benefits in controlling H. pylori infection. We discussed publications in English mostly published since 2020 using keyword search. Curcumin is the main bioactive substance in turmeric. Curcumin inhibited H. pylori growth, urease activity, three cag genes, and biofilms through dose- and strain-dependent activities. Curcumin also displayed numerous anticancer activities such as apoptosis induction, anti-inflammatory and anti-angiogenic effects, caspase-3 upregulation, Bax protein enhancement, p53 gene activation, and chemosensitization. Supplementing triple regimens, the agent increased H. pylori eradication success in three Iranian studies. Bioavailability was improved by liposomal preparations, lipid conjugates, electrospray-encapsulation, and nano-complexation with proteins. The agent was safe at doses of 0.5->4 g daily, the most common (in 16% of the users) adverse effect being gastrointestinal upset. Notably, curcumin favorably influences the intestinal microbiota and inhibits Clostridioides difficile. Previous reports showed the inhibitory effect of curcumin on H pylori growth. Curcumin may become an additive in the therapy of H. pylori infection, an adjunct for gastric cancer control, and an agent beneficial to the intestinal microbiota. Further examination is necessary to determine its optimal dosage, synergy with antibiotics, supplementation to various eradication regimens, and prophylactic potential.

One-Pot Microfluidics to Engineer Chitosan Nanoparticles Conjugated with Antimicrobial Peptides Using "Photoclick" Chemistry: Validation Using the Gastric Bacterium Helicobacter pylori

Surface bioconjugation of antimicrobial peptides (AMP) onto nanoparticles (AMP-NP) is a complex, multistep, and time-consuming task. Herein, a microfluidic system for the one-pot production of AMP-NP was developed. Norbornene-modified chitosan was used for NP production (NorChit-NP), and thiolated-AMP was grafted on their surface via thiol-norbornene "photoclick" chemistry over exposure of two parallel UV LEDs. The MSI-78A was the AMP selected due to its high activity against a high priority (level 2) antibiotic-resistant gastric pathogen: Helicobacter pylori (H. pylori). AMP-NP (113 ± 43 nm; zeta potential 14.3 ± 7 mV) were stable in gastric settings without a cross-linker (up to 5 days in pH 1.2) and bactericidal against two highly pathogenic H. pylori strains (1011 NP/mL with 96 μg/mL MSI-78A). Eradication was faster for H. pylori 26695 (30 min) than for H. pylori J99 (24 h), which was explained by the lower minimum bactericidal concentration of soluble MSI-78A for H. pylori 26695 (32 μg/mL) than for H. pylori J99 (128 μg/mL). AMP-NP was bactericidal by inducing H. pylori cell membrane alterations, intracellular reorganization, generation of extracellular vesicles, and leakage of cytoplasmic contents (transmission electron microscopy). Moreover, NP were not cytotoxic against two gastric cell lines (AGS and MKN74, ATCC) at bactericidal concentrations. Overall, the designed microfluidic setup is a greener, simpler, and faster approach than the conventional methods to obtain AMP-NP. This technology can be further explored for the bioconjugation of other thiolated-compounds.

High-efficiency antibacterial calcium alginate/lysozyme/AgNPs composite sponge for wound healing

Infection poses a significant barrier to effective wound repair, leading to increased inflammatory responses that ultimately result in incomplete and prolonged wound healing. To address this challenge, numerous antibacterial ingredients have been incorporated into dressings to inhibit wound infection. Our previous work demonstrated that lysozyme/silver nanoparticles (LYZ/AgNPs) complexes, prepared using an eco-friendly one-step aqueous method, exhibited excellent antibacterial efficacy with favorable biosafety. To further explore its potential application in advancing wound healing, calcium alginate (CA) with good porosity, water absorption, and water retention capacities was formulated with LYZ/AgNPs to prepare composite sponge (CA/LYZ/AgNPs). As expected, in vivo experiments involving full-thickness skin wound and scald wound healing experiments demonstrated that CA-LYZ-AgNPs composite sponges with excellent biocompatibility exhibited remarkable antibacterial activity against gram-positive bacteria, gram-negative bacteria and fungi, and outperformed the wound healing process efficacy of other commercially available AgNPs-loaded wound dressings. In summary, this work introduces a CA/LYZ/AgNPs sponge featuring exceptional antibacterial efficacy and biocompatibility, thus holding promising potential in wound care applications.

Chitosan nanocomposite for tissue engineering and regenerative medicine: A review

Regenerative medicine and tissue engineering have emerged as a multidisciplinary promising field in the quest to address the limitations of traditional medical approaches. One of the key aspects of these fields is the development of such types of biomaterials that can mimic the extracellular matrix and provide a conducive environment for tissue regeneration. In this regard, chitosan has played a vital role which is a naturally derived linear bi-poly-aminosaccharide, and has gained significant attention due to its biocompatibility and unique properties. Chitosan possesses many unique physicochemical properties, making it a significant polysaccharide for different applications such as agriculture, nutraceutical, biomedical, food, nutraceutical, packaging, etc. as well as significant material for developing next-generation hydrogel and bio-scaffolds for regenerative medicinal applications. Moreover, chitosan can be easily modified to incorporate desirable properties, such as improved mechanical strength, enhanced biodegradability, and controlled release of bioactive molecules. Blending chitosan with other polymers or incorporating nanoparticles into its matrix further expands its potential in tissue engineering applications. This review summarizes the most recent studies of the last 10 years based on chitosan, blends, and nanocomposites and their application in bone tissue engineering, hard tissue engineering, dental implants, dental tissue engineering, dental fillers, and cartilage tissue engineering.

Advancing biofilm management through nanoformulation strategies: a review of dosage forms and administration routes

Biofilms are complex microbial communities formed by the attachment of bacteria or fungi to surfaces encased in a self-produced polymeric matrix. These biofilms are highly resistant to conventional antimicrobial therapies. The resistance mechanisms exhibited by biofilms include low antibiotic absorption, sluggish replication, adaptive stress response, and the formation of dormant-like phenotypes. The eradication of biofilms requires alternative strategies and approaches. Nanotechnological drug delivery systems allow excellent control over the drug chemistry, surface area, particle size, particle shape, and composition of nanostructures. Nanoformulations can enhance the efficacy of antimicrobial agents by improving their bioavailability, stability, and targeted delivery to the site of infection that helps biofilm eradication more effectively. In addition to nanoformulations, the route of administration and choice of dosage forms play a crucial role in treating biofilm infections. Systemic administration of antibiotics is effective in controlling systemic infection and sepsis associated with biofilms. Alternative routes of administration, such as inhalation, vaginal, ocular, or dermal, have been explored to target biofilm infections in specific organs. This review primarily examines the utilisation of nanoformulations in various administration routes for biofilm management. It also provides an overview of biofilms, current approaches, and the drawbacks associated with conventional methods.

Microparticles and nanoparticles-based approaches to improve oral treatment of Helicobacter pylori infection

Helicobacter pylori is a gram-negative, spiral-shaped, flagellated bacterium that colonizes the stomach of half the world's population. Helicobacter pylori infection causes pathologies of varying severity. Standard oral therapy fails in 15-20% since the barriers of the oral route decrease the bioavailability of antibiotics and the intrinsic factors of bacteria increase the rates of resistance. Nanoparticles and microparticles are promising strategies for drug delivery into the gastric mucosa and targeting H. pylori. The variety of building blocks creates systems with distinct colloidal, surface, and biological properties. These features improve drug-pathogen interactions, eliminate drug depletion and overuse, and enable the association of multiple actives combating H. pylori on several fronts. Nanoparticles and microparticles are successfully used to overcome the barriers of the oral route, physicochemical inconveniences, and lack of selectivity of current therapy. They have proven efficient in employing promising anti-H. pylori compounds whose limitation is oral route instability, such as some antibiotics and natural products. However, the current challenge is the applicability of these strategies in clinical practice. For this reason, strategies employing a rational design are necessary, including in the development of nano- and microsystems for the oral route.

Preparation and Primary Bioactivity Evaluation of Novel Water-Soluble Curcumin-Loaded Polymeric Micelles Fabricated with Chitooligosaccharides and Pluronic F-68

Curcumin (CU) is a bioactive compound extracted from turmeric and has various advantages. However, the benefit of CU is limited by its low water solubility (11 ng/mL). This research aimed to fabricate a water-soluble CU nano-formulation with chitooligosaccharides (COS) and pluronic F-68 (PF) utilizing the polymeric micelle method. The optimized curcumin-loaded chitooligosaccharides/pluronic F-68 micelles (COSPFCU) exhibited high encapsulation efficiency and loading capacity (75.57 ± 2.35% and 10.32 ± 0.59%, respectively). The hydrodynamic diameter of lyophilized COSPFCU was 73.89 ± 11.69 nm with a polydispersity index below 0.3. The COSPFCU could be completely redispersed in water and showed high DPPH scavenging ability. Meanwhile, COSPFCU could significantly reduce the cytotoxicity of the RAW 264.7 cells compared to native CU. Furthermore, COSPFCU improved the inhibition of NO release activity at 72.83 ± 2.37% but 33.20 ± 3.41% for the CU, with a low cytotoxicity concentration in the RAW 264.7 cells.

Effect of Polydopamine and Curcumin on Physicochemical and Mechanical Properties of Polymeric Blends

In this study, we prepared composites made from polyvinyl alcohol (PVA), sodium alginate (SA), curcumin (Cur), and polydopamine (PD). The film-forming properties of the composites were researched for potential wound-healing applications. The structures of the polymer blends and composites were studied by FTIR spectroscopy and microscopic observations (AFM and SEM). The mechanical properties were measured using a Zwick Roell testing machine. It was observed that the formation of a polymeric film based on the blend of polyvinyl alcohol and sodium alginate led to the generation of pores. The presence of curcumin in the composite resulted in the alteration of the blend properties. After solvent evaporation, the polymeric blend of PVA, SA, and curcumin formed a stable polymeric film, but the film showed poor mechanical properties. The addition of polydopamine led to an improvement in the mechanical strength of the film and an increase in its surface roughness. A polymeric film of sodium alginate presented the highest surface roughness value among all the studied specimens (66.6 nm), whereas polyvinyl alcohol showed the lowest value (1.60 nm). The roughness of the composites made of PVA/SA/Cur and PVA/SA/Cur/PD showed a value of about 25 nm. Sodium alginate showed the highest values of Young's modulus (4.10 GPa), stress (32.73 N), and tensile strength (98.48 MPa). The addition of PD to PVA/SA/Cur led to an improvement in the mechanical properties. Improved mechanical properties and appropriate surface roughness may suggest that prepared blends can be used for the preparation of wound-healing materials.

Polysaccharides-based nanocarriers enhance the anti-inflammatory effect of curcumin

Curcumin (CUR) has been discovered to have many biological activities, including anti-inflammatory, anti-cancer, anti-oxygenation, anti-human immunodeficiency virus, anti-microbial and exhibits a good effect on the prevention and treatment of many diseases. However, the limited properties of CUR, including the poor solubility, bioavailability and instability caused by enzymes, light, metal irons, and oxygen, have compelled researchers to turn their attention to drug carrier application to overcome these drawbacks. Encapsulation may provide potential protective effects to the embedding materials and/or have a synergistic effect with them. Therefore, nanocarriers, especially polysaccharides-based nanocarriers, have been developed in many studies to enhance the anti-inflammatory capacity of CUR. Consequently, it's critical to review current advancements in the encapsulation of CUR using polysaccharides-based nanocarriers, as well as further study the potential mechanisms of action where polysaccharides-based CUR nanoparticles (the complex nanoparticles/Nano CUR-delivery systems) exhibit their anti-inflammatory effects. This work suggests that polysaccharides-based nanocarriers will be a thriving field in the treatment of inflammation and inflammation-related diseases.

Surface engineering of chitosan nanosystems and the impact of functionalized groups on the permeability of model drug across intestinal tissue

Surface attributes of nanocarriers are crucial to determine their fate in the gastrointestinal (GI) tract. Herein, we have functionalized chitosan with biochemical moieties including rhamnolipid (RL), curcumin (Cur) and mannose (M). FTIR spectra of functionalized chitosan nanocarriers (FCNCs) demonstrated successful conjugation of M, Cur and RL. The functional moieties influenced the entrapment of model drug i.e., coumarin-6 (C6) in FCNCs with payload-hosting and non-leaching behavior i.e., >91 ± 2.5 % with negligible cumulative release of <2 % for 5 h in KREB, which was further verified in the simulated gastric and intestinal fluids. Consequently, substantial difference in the size and zeta potential was observed for FCNCs with different biochemical moieties. Scanning electron microscopy and atomic force microscopy of FCNCs displayed well-dispersed and spherical morphology. In addition, in vitro cytotoxicity results of FCNCs confirmed their hemocompatibility. In the ex-vivo rat intestinal models, FCNCs displayed a time-dependent-phenomenon in cellular-uptake and adherence. However, apparent-permeability-coefficient and flux values were in the order of C6-RL-FCNCs > C6-M-FCNCs > C6-Cur-FCNCs = C6-CNCs > Free-C6. Furthermore, the transepithelial electrical resistance revealed the FCNCs mediated recovery of membrane-integrity with reversible tight junctions opening. Thus, FCNCs have the potential to overcome the poor solubility and/or permeability issues of active pharmaceutical ingredients and transform the impact of functionalized-nanomedicines in the biomedical industry.

Evaluation of photodynamic therapy on nanoparticles and films loaded-nanoparticles based on chitosan/alginate for curcumin delivery in oral biofilms

Nanoparticles and nanoparticle-loaded films based on chitosan/sodium alginate with curcumin (CUR) are promising strategies to improve the efficacy of antimicrobial photodynamic therapy (aPDT) for the treatment of oral biofilms. This work aimed to develop and evaluate the nanoparticles based on chitosan and sodium alginate encapsulated with CUR dispersed in polymeric films associated with aPDT in oral biofilms. The NPs were obtained by polyelectrolytic complexation, and the films were prepared by solvent evaporation. The photodynamic effect was evaluated by counting Colony Forming Units (CFU/mL). Both systems showed adequate characterization parameters for CUR release. Nanoparticles controlled the release of CUR for a longer period than the nanoparticle-loaded films in simulated saliva media. Control and CUR-loaded nanoparticles showed a significant reduction of 3 log10 CFU/mL against S. mutans biofilms, compared to treatment without light. However, biofilms of S. mutans showed no photoinactivation effect using films loaded with nanoparticles even in the presence of light. These results demonstrate the potential of chitosan/sodium alginate nanoparticles associated with aPDT as carriers for the oral delivery of CUR, offering new possibilities to improve the treatment of dental caries and infections. This work will contribute to advances in the search for innovative delivery systems in dentistry.

Scientometric Research on Trend Analysis of Nano-Based Sustained Drug Release Systems for Wound Healing

Nanomaterials, such as the nanoparticle (NP), nanomicelle, nanoscaffold, and nano-hydrogel, have been researched as nanocarriers for drug delivery more and more recently. Nano-based drug sustained release systems (NDSRSs) have been used in many medical fields, especially wound healing. However, as we know, no scientometric analysis has been seen on applying NDSRSs in wound healing, which could be of great importance to the relevant researchers. This study collected publications from 1999 to 2022 related to NDSRSs in wound healing from the Web of Science Core Collection (WOSCC) database. We employed scientometric methods to comprehensively analyze the dataset from different perspectives using CiteSpace, VOSviewer, and Bibliometrix. The results indicated that China published the most significant number of documents in the last two decades, Islamic Azad Univ was the most productive institution, and Jayakumar, R was the most influential author. Regarding the analysis of keywords, trend topics indicate that "antibacterial", "chitosan (CS)", "scaffold", "hydrogel", "silver nanoparticle", and "growth factors (GFs)" are the hot topics in recent years. We anticipate that our work will provide a comprehensive overview of research in this field and help scholars better understand the research hotspots and frontiers in this area, thus inspiring further explorations in the future.

Cynometra cauliflora essential oils loaded-chitosan nanoparticles: Evaluations of their antioxidant, antimicrobial and cytotoxic activities

Nanoencapsulation has appeared as an alternative approach to protect the bioactive constituents of essential oils (EOs) and to improve their properties. In this study, Cynometra cauliflora essential oils (CCEOs) were nanoencapsulated in chitosan nanoparticles (CSNPs) using an emulsion-ionic gelation technique. Transmission electron microscopy (TEM) images illustrated a well dispersion and spherical shape of C. cauliflora EOs-loaded chitosan nanoparticles (CCEOs-CSNPs) with an average size of less than 100 nm. In addition to that, Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS) and X-ray diffraction (XRD) analyses revealed the success of CCEOs nanoencapsulation. The encapsulation efficiency (EE) was in the range of 38.83% to 44.16% while the loading capacity (LC) reached 32.55% to 33.73%. The antioxidant activity (IC₅₀) of CCEOs-CSNPs was ranged from 21.65 to 259.13 μg/mL when assessed using DPPH radical scavenging assay. CCEOs-CSNPs showed an appreciable antimicrobial effects on diabetic wound microorganisms. Notably, cytotoxic effects against human breast cancer MCF-7 and MDA-MB-231 cells recorded IC₅₀ of 3.72-17.81 μg/mL and 16.24-17.65 μg/mL, respectively, after 72 h treatment. Interestingly, no cytotoxicity against human breast normal MCF-10A cells was observed. Thus, nanoencapsulation using CSNPs could improve the properties of CCEOs in biomedical related applications.