Preparation of 5-fluorouracil-loaded chitosan nanoparticles and study of the sustained release in vitro and in vivo

Urea intercalated encapsulated microalgae composite hydrogels for slow-release fertilizers

In agriculture, hydrogels can be addressed for effective operation of water and controlled-release fertilizers. Hydrogels have a significant ability for retaining water and improving nutrient availability in soil, enhancing plant growth while reducing water and fertilizer usage. This work aimed to prepare a hydrogel composite based on microalgae and biopolymers including chitosan and starch for use as a soil conditioner. The hydrogel composite was characterized by FTIR, XRD, and SEM. All hydrogel properties were studied including swelling degree, biodegradability, water-holding capacity, water retention, and re-swelling capacity in soil and water. The urea fertilizer loading and releasing behavior of the prepared hydrogels were investigated. The results revealed that the range of the maximal urea loading was between 99 and 440%, and the kinetics of loading was fitted with Freundlich model. The urea release % exhibited 78-95%, after 30 days, and the kinetics of release was fitted with zero-order, Higuchi, and Korsmeyer-Peppas models. Furthermore, the prepared hydrogels obtained a significant water-holding capacity, after blending soil (50 g) with small amount of hydrogels (1 g), the capacity increased in the range of 99.4-101.5%. In sum, the prepared hydrogels have the potential to be applied as a soil conditioner.

Antibacterial, Antifungal, and Cytotoxic Potential of PlumbaginLoaded pH-Responsive Vaginal Nanoformulations

Plumbagin is a naphthoquinone from the roots of the Plumbago species and exhibits anticancer activity. Translational usage of plumbagin in biomedical sciences is restricted due to its poor solubility and bioavailability. Therefore, pH-responsive plumbagin-loaded vaginal nanoformulations with polylactic acid (PLA)-chitosan polymeric coat were fabricated by inotropic gelation technique. Among the four (F1, F2, F3, F4) nanoformulations prepared, F3 exhibited good interaction of polymers with plumbagin as evidenced by FTIR, XRD, and thermal analysis. The positive zeta potential (48.4 ± 5.57 mV), optimal size (694 ± 65.76 nm), low PDI (0.157), and good encapsulation efficiency (77.8 ± 3.62%) of F3 were significant. The indirect method of drug loading (58.35 ± 5.00%) confirmed the drug content of about 495.44 ± 5.00 µg of plumbagin in 1 mg of F3. The drug loading pattern was confirmed by TEM analysis, and the spherical morphology of the nanocomposite was confirmed by SEM analysis. F3 formulation showed 46% and 25.2% of drug release in 24 h in simulated vaginal fluid at pH 4.5 and 7 respectively with sustained release and hydrolyses of lactic acid from PLA. Among all the nanoformulations evaluated, nanoformulation F3 with promising physicochemical properties showed good antifungal and antibacterial activity against various fungal and bacterial strains. F3 exhibited potent cytotoxicity with an IC50 of 3.6 ± 0.12 µg/ml for HeLa and an IC50 of 0.81 ± 0.01 µg/ml for SiHa cells. Altogether, the nanoformulation F3 exhibited potent antimicrobial activity against vaginal infections and cytotoxicity against cervical cancer cell lines.

Selective binding of cationic fibrinogen-mimicking chitosan nanoparticles to activated platelets and efficient drug release for antithrombotic therapy

Thrombosis is the main cause of catastrophic events including ischemic stroke, myocardial infarction and pulmonary embolism. Acetylsalicylic acid (ASA) therapy offers a desirable approach to antithrombosis through a reduction of platelet reactivity. However, major bleeding complications, severe off-target side effects, and resistance or nonresponse to ASA greatly attenuate its clinical outcomes. Herein, we report a cationic fibrinogen-mimicking nanoparticle, denoted as ASA-RGD-CS@TPP, to achieve activated-platelet-targeted delivery and efficient release of ASA for safer and more effective antithrombotic therapy. This biomimetic antithrombotic system was prepared by one-pot ionic gelation between cationic arginine-glycine-aspartic acid (RGD)-grafted chitosan (RGD-CS) and anionic tripolyphosphate (TPP). The platform exhibited selective binding to activated platelets, leading to efficient release of ASA and subsequent attenuation of platelet functions, including the remarkable inhibition of platelet aggregation through a potent blockage of cyclooxygenase-1 (COX-1). After intravenous administration, ASA-RGD-CS@TPP displayed significantly prolonged circulation time and successful prevention of thrombosis in a mouse model. ASA-RGD-CS@TPP was demonstrated to significantly enhance antithrombotic therapy while showing minimal coagulation and hemorrhagic risks and excellent biocompatibility in vivo as compared to free ASA. This platform provides a simple, safe, effective and targeted strategy for the development of antithrombotic nanomedicines.

Synthesis of poly(ionic liquid-OH) mediated deacetylated chitin and its hydrogels: A study on their applications in controlled release of paracetamol and urea

Due to the biodegradable and biocompatible nature of chitin and chitosan, they are extensively used in the synthesis of hydrogels for various applications. In this work, deacetylation of chitin is carried out with alkaline poly(dimethyldiallylammonium-hydroxide) that gave a higher amount of water-soluble chitin (with 84 % of the degree of deacetylation = chitosan0.84) compared to deacetylation using NaOH. The water-soluble chitosan0.84 is used as intercalating chains for the preparation of acrylic acid and vinylimidazole-based hydrogels. The quaternization of imidazole groups is done with 1,ω-dibromoalkanes, which sets off the crosslinking in the above polymer network. A set of three chitosan0.84 intercalated hydrogels, namely Cs-C4-hydrogel, Cs-C5-hydrogel, and Cs-C10-hydrogel are prepared bearing butyl, pentyl, and decyl chains as respective crosslinkers. The swell ratios of these intercalated hydrogels are compared with those of non-intercalated hydrogels (C4-hydrogel, C5-hydrogel, and C10-hydrogel). Chitosan0.84 intercalated Cs-C10-hydrogel has excellent swelling properties (2330 % swelling ratio) among six synthesized hydrogels. SEM analysis reveals that decyl crosslinker-bearing hydrogels are highly porous. The multi-functionality of Cs-C10-hydrogel and C10-hydrogel is explored towards -the controlled release of paracetamol/urea, and methyleneblue dye absorption. These studies disclose that chitosan0.84 intercalated hydrogels are showing superior-swelling behavior, high paracetamol/urea loading capacities and better dye entrapment than their non-intercalated counterparts.

Revolutionizing Cancer Treatment: Biopolymer-Based Aerogels as Smart Platforms for Targeted Drug Delivery

Cancer stands as a leading cause of global mortality, with chemotherapy being a pivotal treatment approach, either alone or in conjunction with other therapies. The primary goal of these therapies is to inhibit the growth of cancer cells specifically, while minimizing harm to healthy dividing cells. Conventional treatments, often causing patient discomfort due to side effects, have led researchers to explore innovative, targeted cancer cell therapies. Thus, biopolymer-based aerogels emerge as innovative platforms, showcasing unique properties that respond intelligently to diverse stimuli. This responsiveness enables precise control over the release of anticancer drugs, enhancing therapeutic outcomes. The significance of these aerogels lies in their ability to offer targeted drug delivery with increased efficacy, biocompatibility, and a high drug payload. In this comprehensive review, the author discuss the role of biopolymer-based aerogels as an emerging functionalized platforms in anticancer drug delivery. The review addresses the unique properties of biopolymer-based aerogels showing their smart behavior in responding to different stimuli including temperature, pH, magnetic and redox potential to control anticancer drug release. Finally, the review discusses the application of different biopolymer-based aerogel in delivering different anticancer drugs and also discusses the potential of these platforms in gene delivery applications.

Controlled delivery of 5-fluorouracil from monodisperse chitosan microspheres prepared by emulsion crosslinking

This work aims to determine the optimal conditions for emulsion cross-linking of chitosan (CHS) with various molecular weights using glutaraldehyde as a cross-linking agent to produce 5-fluorouracil-loaded CHS microspheres (5-FU/CHS). Their drug loading and encapsulation efficiencies are found to be in the range of 3.87-12.35% and 20.13-70.45%, respectively. The dynamic light scattering results show that 5-FU/CHS microspheres are micron-sized with a uniform size distribution, and the scanning electron microscopy results show that they are spherical. The results of thermogravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy demonstrate that 5-FU is successfully incorporated into the microspheres. The in vitro release tests show that 5-FU/CHS have a prolonged, pH-responsive release pattern of 5-FU, and the cumulative release rate under acidic condition is much larger than that under neutral conditions. The drug release kinetic analysis further demonstrates that the release of 5-FU can be well described by the Fickian diffusion model.

Effectiveness and safety of intraoperative intraperitoneal 5-Fu drug implantation in patients with colorectal cancer: a retrospective cohort study

PURPOSE

The purpose of this clinical study was to evaluate the efficacy and safety of intraoperative chemotherapy (IOC) with intraoperative intraperitoneal implantation of 5-fluorouracil (5-FU) in colorectal cancer (CRC) patients.

METHODS

In this study, 165 patients who underwent colorectal radical surgery were selected, of whom 111 in the experimental group received surgical treatment with an intraperitoneal 5-fluorouracil (5-FU) implantation. Fifty-four patients who did not undergo intraperitoneal implantation of 5-FU were matched to compare the progression-free survival (PFS) and overall survival (OS) with the former.

RESULTS

We also studied the differences in the changes of different biochemical indicators between the two groups before and after surgery, and there were significant differences in leukocytes, neutrophils, and lymphocytes before and after (P < 0.05), while for sodium ions, potassium ions, platelets, alanine transaminase, aspartate transaminase, creatinine, urea, and albumin, there were no significant differences. This may be related to the intraperitoneal chemotherapy implant entering the blood circulation. For 5-year OS, there were 85/111 (76.58%) in the 5-FU group (P = 0.013) and 35/54 (64.81%) in the control group; for 5-year PFS, there were 84/111 (75.68%) in the 5-FU group and 29/54 (53.70%) in the control group (P = 0.02). All the experimental groups were better than the control group with a significant difference in the experimental results.

CONCLUSION

For CRC surgery patients, intraperitoneal implantation of slow-release 5-FU drugs, which is a safe and simple procedure, can improve the prognosis of the patients.

CLINICAL TRIAL REGISTRATION

No clinical trials were performed in the study.

Multifunctional chitosan-bimetallic nanocarrier deliver 5-fluorouracil for enhanced treatment of pancreatic and triple-negative breast cancer

This work aimed to prepare multifunctional aptamer-conjugated, photothermally responsive 5-fluorouracil (5fu)-loaded chitosan-bimetallic (Au/Pd) nanoparticles (APT-CS-5fu-Au/Pd NPs) for improved cytotoxicity in two cancer cell lines (PANC-1 and MDA-MD 231). The CS-5fu-Au/Pd NPs were polydispersed with a size of 34.43 ± 1.59 nm. FTIR analysis indicated the presence of CS, 5fu in CS-5fu-Au/Pd NPs. The 2 theta degrees in CS-5fu-Au/Pd NPs accounted for CS and Au/Pd. Additionally, AGE revealed the conjugation of APT in CS-5fu-Au/Pd NPs. The APT-CS-5fu-Au/Pd NPs (180 μg/mL) with NIR treatment increased the temperature to >50 °C. The optimized 5fu input was 0.075 % in CS-5fu-Au/Pd NPs, exhibiting a hydrodynamic size of 112.96 ± 17.23 nm, DEE of 64.2 ± 3.77 %, and DLE of 11.1 ± 0.65 %. A higher level of 5fu release (69.8 ± 2.78 %) was observed under pH 5.4 at 74 h. In conclusion, NIR-APT-CS-5fu-Au/Pd NPs did not cause toxicity to RBC and Egg CAM, but increased cytotoxicity in MDA-MB 231 and PANC-1 cells by triggering oxidative stress-mediated cell death.

Specifics of Pharmacokinetics and Biodistribution of 5-Fluorouracil Polymeric Complex

One of the promising and relevant directions in the treatment of oncological diseases is currently the development of a system for the delivery of antitumor drugs based on polyanions. Therefore, the aim of this work was to study the specifics of pharmacokinetics and biodistribution of a 5-Fluorouracil polymeric complex compared with commercial 5-Fluorouracil.

MATERIALS AND METHODS

Monomeric methacrylic acid was used to synthesize polymers; 2-phenylpropane-2-ilbenzodithioate was used for the synthesis of poly(methacrylic acid). To study the molecular-weight characteristics of poly(methacrylic acid) by gel permeation chromatography, an experimental neoplasm model was obtained by grafting PC-1 cancer cells. Blood samples were drawn from the tail vein at different points in time. The rats were sacrificed via decapitation after drawing the last pharmacokinetic blood sample. To study the biodistribution, internal organs were isolated and analyzed. The measurements were carried out by high-performance liquid chromatography.

RESULTS

Our results demonstrate that incorporation in a polymeric complex changes the pharmacokinetics and biodistribution profile of 5-FU. The polymeric complex was shown to accumulate to a higher level in the lung and spleen.

CONCLUSION

The results obtained are the basis for further studies to verify the efficacy of the 5-Fluorouracil polymeric complex.

Characterization of Chitosan-Hybridized Diatomite as Potential Delivery Systems of Oxaliplatin and 5-Fluorouracil Drugs: Equilibrium and Release Kinetics

The current work involves the modification of diatomite's biosiliceous frustules employing chitosan polymer chains (CS/Di) to serve as low-cost, biocompatible, multifunctional, and enhanced pharmaceutical delivery systems for 5-fluorouracil (5-Fu) together with oxaliplatin (OXPL). The CS/Di carrier displayed strong loading characteristics, notably at saturation (249.17 mg/g (OXPL) and 267.6 mg/g (5-Fu)), demonstrating a substantial 5-Fu affinity. The loading of the two types of medications onto CS/Di was conducted based on the kinetic behaviors of the conventional pseudo-first-order theory (R2 > 0.90). However, while the loading of OXPL follows the isotherm assumptions of the classic Langmuir model (R2 = 0.99), the loading of 5-Fu displays Fruendlich isotherm properties. Therefore, the 5-Fu loading displayed physical, heterogeneous, and multilayer loading properties, whereas the loading of OXPL occurred in homogeneous and monolayer form. The densities of occupied active sites of CS/Di were 37.19 and 32.8 mg/g for the sequestrations of OXPL and 5-Fu, respectively. Furthermore, by means of multimolecular processes, each loading site of CS/Di can bind up to 8 molecules of OXPL and 9 molecules of 5-Fu in a vertical orientation. This observation explains the higher loading capacities of 5-Fu in comparison to OXPL. The loading energies, which exhibit values <40 kJ/mol, provide confirmation of the dominant and significant consequences of physical processes as the regulating mechanisms. The release patterns of OXPL and 5-Fu demonstrate prolonged features over a duration of up to 120 h. The release kinetic simulation and diffusion exponents which are more than 0.45 provide evidence of the release of OXP and 5-Fu via non-Fickian transportation characteristics and the erosion/diffusion mechanism. The CS/Di carrier exhibited a substantial enhancement in the cytotoxicity of OXPL and 5-Fu against HCT-116 carcinoma cell lines, resulting in a reduction in cell viability by 4.61 and 2.26% respectively.

Therapeutic potential of nanotechnology in reproduction disorders and possible limitations

One of the prominent peculiarities of nanoparticles (NPs) is their ability to cross biological barriers. Therefore, the development of NPs with different properties has great therapeutic potential in the area of reproduction because the association of drugs, hormones and other compounds with NPs represents an alternative for delivering substances directly at a specific site and for treatment of reproductive problems. Additionally, lipid-based NPs can be taken up by the tissues of patients with ovarian failure, deep endometriosis, testicular dysfunctions, etc., opening up new perspectives for the treatment of these diseases. The development of nanomaterials with specific size, shape, ligand density and charge certainly will contribute to the next generation of therapies to solve fertility problems in humans. Therefore, this review discusses the potential of NPs to treat reproductive disorders, as well as to regulate the levels of the associated hormones. The possible limitations of the clinical use of NPs are also highlighted.

Anticancer Drug-Loaded Chitosan Nanoparticles for In Vitro Release, Promoting Antibacterial and Anticancer Activities

Targeted drug delivery to tumor cells may be possible using nanoparticles containing human therapeutic drugs. The present study was carried out to develop cisplatin (CP) and 5-fluorouracil (FA) encapsulated chitosan nanoparticles (CSNPs), crosslinked with sodium tripolyphosphate (TPP) by an ionic gelation method and in vitro release, promoting antibacterial and anticancer activities. The prepared CSNPs, before and after CP and FA encapsulation, have been studied using various characterization techniques such as FTIR, XRD, SEM, and TEM-SAED patterning. The composites were well-dispersed, with an average particle size diameter of about 395.3 ± 14.3 nm, 126.7 ± 2.6 nm, and 82.5 ± 2.3 nm, respectively. In vitro release studies indicated a controlled and sustained release of CP and FA from the CSNPs, with the release amounts of 72.9 ± 3.6% and 94.8 ± 2.9%. The antimicrobial activity of the CSNPs-FA (91.37 ± 4.37% and 89.28 ± 3.19%) showed a significantly better effect against E. coli and S. aureus than that shown by the CSNPs-CP (63.41 ± 3.84% and 57.62 ± 4.28%). The HCT-116 cell lines were selected for in vitro cell cytotoxicity and live/dead assay to evaluate the preliminary anticancer efficacy of the CSNPs-CP and CSNPs-FA towards successfully inhibiting the growth of cancer cells.

Synthesis and Characterization of Methoxy-Exfoliated Montmorillonite Nanosheets as Potential Carriers of 5-Fluorouracil Drug with Enhanced Loading, Release, and Cytotoxicity Properties

Natural bentonite clay (BE) underwent modification steps that involved the exfoliation of its layers into separated nanosheets (EXBE) and further functionalization of these sheets with methanol, forming methoxy-exfoliated bentonite (Mth/EXBE). The synthetically modified products were investigated as enhanced carriers of 5-fluorouracil as compared to raw bentonite. The modification process strongly induced loading properties that increased to 214.4 mg/g (EXBE) and 282.6 mg/g (Mth/EXBE) instead of 124.9 mg/g for bentonite. The loading behaviors were illustrated based on the kinetic (pseudo-first-order model), classic isotherm (Langmuir model), and advanced isotherm modeling (monolayer model of one energy). The Mth/EBE carrier displays significantly higher loading site density (95.9 mg/g) as compared to EXBE (66.2 mg/g) and BE (44.9 mg/g). The loading numbers of 5-Fu in each site of BE, EXBE, and Mth/EXBE (>1) reflect the vertical orientation of these loaded ions involving multi-molecular processes. The loading processes that occurred appeared to be controlled by complex physical and weak chemical mechanisms, considering both Gaussian energy (<8 KJ/mol) as well as loading energy (<40 KJ/mol). The releasing patterns of EXBE and Mth/EXBE exhibit prolonged and continuous properties up to 100 h, with Mth/EXBE displaying much faster behaviors. Based on the release kinetic modeling, the release reactions exhibit non-Fickian transport release properties, validating cooperative diffusion and erosion release mechanisms. The cytotoxicity of 5-Fu is also significantly enhanced by these carriers: 5-Fu/BE (8.6% cell viability), 5-Fu/EXBE (2.21% cell viability), and 5-Fu/Mth/EXBE (0.73% cell viability).

Marine Microbial Polysaccharides: An Untapped Resource for Biotechnological Applications

As the largest habitat on Earth, the marine environment harbors various microorganisms of biotechnological potential. Indeed, microbial compounds, especially polysaccharides from marine species, have been attracting much attention for their applications within the medical, pharmaceutical, food, and other industries, with such interest largely stemming from the extensive structural and functional diversity displayed by these natural polymers. At the same time, the extreme conditions within the aquatic ecosystem (e.g., temperature, pH, salinity) may not only induce microorganisms to develop a unique metabolism but may also increase the likelihood of isolating novel polysaccharides with previously unreported characteristics. However, despite their potential, only a few microbial polysaccharides have actually reached the market, with even fewer being of marine origin. Through a synthesis of relevant literature, this review seeks to provide an overview of marine microbial polysaccharides, including their unique characteristics. In particular, their suitability for specific biotechnological applications and recent progress made will be highlighted before discussing the challenges that currently limit their study as well as their potential for wider applications. It is expected that this review will help to guide future research in the field of microbial polysaccharides, especially those of marine origin.

Amelioration of Cancer Employing Chitosan, Its Derivatives, and Chitosan-Based Nanoparticles: Recent Updates

The limitations associated with the conventional treatment of cancer have necessitated the design and development of novel drug delivery systems based mainly on nanotechnology. These novel drug delivery systems include various kinds of nanoparticles, such as polymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid carriers, hydrogels, and polymeric micelles. Among the various kinds of novel drug delivery systems, chitosan-based nanoparticles have attracted the attention of researchers to treat cancer. Chitosan is a polycationic polymer generated from chitin with various characteristics such as biocompatibility, biodegradability, non-toxicity, and mucoadhesiveness, making it an ideal polymer to fabricate drug delivery systems. However, chitosan is poorly soluble in water and soluble in acidic aqueous solutions. Furthermore, owing to the presence of reactive amino groups, chitosan can be chemically modified to improve its physiochemical properties. Chitosan and its modified derivatives can be employed to fabricate nanoparticles, which are used most frequently in the pharmaceutical sector due to their possession of various characteristics such as nanosize, appropriate pharmacokinetic and pharmacodynamic properties, non-immunogenicity, improved stability, and improved drug loading capacity. Furthermore, it is capable of delivering nucleic acids, chemotherapeutic medicines, and bioactives using modified chitosan. Chitosan and its modified derivative-based nanoparticles can be targeted to specific cancer sites via active and passive mechanisms. Based on chitosan drug delivery systems, many anticancer drugs now have better effectiveness, potency, cytotoxicity, or biocompatibility. The characteristics of chitosan and its chemically tailored derivatives, as well as their use in cancer therapy, will be examined in this review.

Novel carboxymethyl cellulose-halloysite-polyethylene glycol nanocomposite for improved 5-FU delivery

Drug nano-carriers are crucial for achieving targeted treatment against cancer disorders with minimal side effects. In this study, a pH-responsive nanocomposite based on halloysite nanotube (HNT) coated with carboxymethyl cellulose (CMC)/polyethylene glycol (PEG) hydrogel for controlled delivery of 5-Fluorouracil (5-FU), a hydrophobic chemotherapy drug prescribed for different types of cancers was synthesized for the first time using the water-in-oil-in-water (W/O/W) technique. The developed CMC/PEG/HNT/5-FU nanocomposite was characterized by dynamic light scattering (DLS), zeta potential, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Field emission scanning electron microscope (FE-SEM) to get information about the particle size, surface charge, interactions between functional groups, crystalline structure and morphology, respectively. High efficiencies in terms of drug entrapment and loading (46 % and 87 %, respectively) were attained. In-vitro drug release results revealed an improved and sustained 5-FU delivery in an acid environment compared to the physiological medium, corroborating the pH-sensitivity of the developed nano-carrier. Flow cytometry and MTT assays demonstrated that the 5-FU loaded nanocomposite had considerable cytotoxicity on MCF-7 breast cancer cells while it is not toxic against L929 fibroblast cells. The nanocomposite synthesized herein could serve as a platform for the pH-sensitive release of anti-cancer drugs.

Design of novel polyurethane-based ionene nanocarriers for cancer therapy: Synthesis, in-vitro, and in-vivo studies

New strategies for constructing versatile nanocarriers are needed for cancer therapy to overcome the multiple challenges of targeted delivery. This work explores the advantages of polyurethane with main-chain quaternary ammonium salt moieties (ionene) as a novel carrier for targeted drug delivery. We have developed a novel cationic soybean oil-based polyurethane ionene nanocarrier (CPUI) that can act as an effective anticancer agent and efficiently deliver the anticancer drug 5-fluorouracil (5FU). We also report a potential anticancer drug delivery system targeting the folate receptor. In vitro experiments with blank CPUI carriers on the 4T1 (mouse breast cancer cell line) and the NIH-3T3 (mouse fibroblast cell line) revealed high cytotoxicity for the cancer cells but only low cytotoxicity for the normal fibroblast cells. The CPUI nanoparticles were readily loaded with 5FU (5FU-CPUI) in water using electrostatic interactions between the cationic quaternary ammonium groups of ionene and the anionic 5FU. The in vivo study in mice with tumors showed that the blank CPUI carriers significantly inhibited tumor growth, even more than the free drug (5FU). The inhibitory effect on tumor growth was slightly enhanced when the carriers were loaded with 5FU. The prepared nanoparticles had a high loading capacity of 41.8 %. Further enhancement of the inhibitory effect was observed when folic acid (FA) was added as a targeting moiety to the system via ion exchange with the bromine counterion of the quaternary ammonium moieties. The results suggest that the efficacy of FA-CPUI-5FU nanoparticles as vehicles for drug delivery can be enhanced via folate receptor (FR) mediated endocytosis in 4T1 cells and these novel nanocarriers may provide a potential platform for effective targeted drug delivery to tumor tissue and breast cancer therapy in the clinic.

Rapidly separable microneedle patch for the controlled and sustained release of 5-fluorouracil

5-Fluorouracil (5-FU) is frequently used in the treatment of tumors and swollen tissues. However, traditional administration methods can result in poor patient compliance and require to administrate frequently due to the short T_1/2 of 5-FU. Herein, the 5-FU@ZIF-8 loaded nanocapsules were prepared using multiple emulsion solvent evaporation methods to enable the controlled and sustained release of 5-FU. To decrease the drug release rate and enhance patient compliance, the obtained pure nanocapsules were added to the matrix to fabricate rapidly separable microneedles (SMNs). The entrapment efficiency (EE%) of 5-FU@ZIF-8 loaded nanocapsules was in the range of 41.55-46.29 %, and the particle size of ZIF-8, 5-FU@ZIF-8, and 5-FU@ZIF-8 loaded nanocapsules were 60 nm, 110 nm, and 250 nm respectively. According to the release study in vivo and in vitro, we concluded that 5-FU@ZIF-8 nanocapsules could achieve the sustained release of 5-FU and that the burst release of nanocapsules could be elegantly handled by incorporating nanocapsules into the SMNs. What's more, the use of SMNs could improve patient compliance due to the rapid separation of needles and backing of SMNs. The pharmacodynamics study also revealed that the formulation would be a better choice for the treatment of scars due to the advantages of painlessness, separation ability, and high delivery efficiency. In conclusion, the SMNs containing 5-FU@ZIF-8 loaded nanocapsules could serve as a potential strategy for some skin diseases therapy with controlled and sustained drug release behavior.

Chitosan Nanoparticles as Oral Drug Carriers

The use of nanoparticles as drug delivery systems has increased in importance in the last decades. Despite the disadvantages of difficulty swallowing, gastric irritation, low solubility, and poor bioavailability, oral administration stands out as the most widely used route for therapeutic treatments, though it may not always be the most effective route. The effect of the first hepatic pass is one of the primary challenges that drugs must overcome to carry out their therapeutic effect. For these reasons, controlled-release systems based on nanoparticles synthesized from biodegradable natural polymers have been reported to be very efficient in enhancing oral delivery in multiple studies. Chitosan has been shown to have an extensive variability of properties and roles in the pharmaceutical and health fields; of its most important properties are the ability to encapsulate and transport drugs within the body and enhance the drug interaction with the target cells, which improves the efficacy of the encapsulated drugs. The physicochemical properties of chitosan give it the ability to form nanoparticles through multiple mechanisms, which will be addressed in this article. The present review article focuses on highlighting the applications of chitosan nanoparticles for oral drug delivery.

Chitosan loaded RNA polymerase inhibitor nanoparticles increased attenuation in toxin release from Streptococcus pneumonia

Background

Multidrug-resistant (MDR) bacterial infections have become an emerging health concern around the world. Antibiotics resistance among S. pneumoniae strains increased recently contributing to increase in incidence of pneumococcal infection. This necessitates the discovery of novel antipnemococcal such as compound C3-005 which target the interaction between RNA polymerase and σ factors. Chitosan nanoparticles (CNPs) exhibited antibacterial activity including S. pneumonia. Therefore, the aims of the current investigation were to formulate CNPs loaded with C3-005 and characteristic their antimicrobial properties against S. pneumonia.

Methods

The CNPs and C3-005 loaded CNPs were produced utilizing ionic gelation method, and their physicochemical characteristics including particle size, zeta potential, polydispersity index (PDI), encapsulation efficiency (EE%), and in vitro release profile were studied. Both differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FTIR) were used for chemical characterization. The synthesized NPs' minimum inhibitory concentration (MIC) was determined using killing assay and broth dilution method, and their impact on bacteria induced hemolysis were also studied.

Results

The NPs encapsulating C3-005 were successfully prepared with particle size of 343.5 nm ± 1.3, zeta potential of 29.8 ± 0.37, and PDI of 0.20 ± 0.03. 70 % of C3-005 were encapsulated in CNPs and sustained release pattern of C3-005 from CNPs was revealed by an in vitro release study. CNPs containing C3-005 exhibited higher antipnomcoccal activity with MIC₅₀ of 30 µg/ml when compared with C3-005 and empty CNPs alone. The prepared C3-CNPs showed a reduction of bacterial hemolysis in a concentration-related (dependent) manner and was higher than C3-005 alone.

Conclusions

The findings of this study showed the potential for using C3-005 loaded CNPs to treat pneumococcal infection.

Molecular dynamic and in vitro evaluation of chitosan/tripolyphosphate nanoparticles as an insulin delivery system at two different pH values

Understanding the atomic interaction mechanism between chitosan and insulin at different pH levels is essential in the design of chitosan-based drug-delivery systems. In the present study, insulin-loaded nanoparticles were prepared via ionic gelation of tripolyphosphate (TPP) and chitosan with 76 ± 5.5% encapsulation efficiency. Our results showed that the nanoparticles were spherical with a size of 254 nm. Furthermore, the in vitro release profile of insulin was evaluated for two different pH levels. The release of insulin from nanoparticles after 48 h at pH 4.0 was 92%, compared to 56% at pH 7.4. The kinetics of the release were best fitted by the Weibull equation, which described a burst release in the first five hours followed by a sustained insulin release for up to 48 h. Moreover, we designed a long single chain chitosan (128 kDa)/TPP nanoparticles in real size for the first time and studied the system behavior in acidic and neutral environments using molecular dynamic simulation for 40 nanoseconds (ns). Our results showed that chitosan chains opened more with higher root-mean-square deviation (RMSD) values at pH 4.0 than at pH 7.4. Also, RMSD plots for insulin and TPP molecules showed that insulin molecules diffused away from chitosan chains, and that TPP were randomly dispersed further away from the chitosan chain in an acidic medium than in a neutral one. The in silico studies were in agreement with our in vitro data. Thus self-assembled chitosan/TPP nanoparticles show promise as a means to release protein drugs in acidic environments.Communicated by Ramaswamy H. Sarma.

Preparation and Characterization of Salsalate-Loaded Chitosan Nanoparticles: In Vitro Release and Antibacterial and Antibiofilm Activity

The controlled-release characteristic of drug delivery systems is utilized to increase the residence time of therapeutic agents in the human body. This study aimed to formulate and characterize salsalate (SSL)-loaded chitosan nanoparticles (CSNPs) prepared using the ionic gelation method and to assess their in vitro release and antibacterial and antibiofilm activities. The optimized CSNPs and CSNP-SSL formulation were characterized for particle size (156.4 ± 12.7 nm and 132.8 ± 17.4 nm), polydispersity index (0.489 ± 0.011 and 0.236 ± 132 0.021), zeta potential (68 ± 16 mV and 37 ± 11 mV), and entrapment efficiency (68.9 ± 2.14%). Physicochemical features of these nanoparticles were characterized using UV-visible and Fourier transform infrared spectroscopy and X-ray diffraction pattern. Scanning electron microscopy studies indicated that CSNPs and CSNP-SSL were spherical in shape with a smooth surface and their particle size ranged between 200 and 500 nm. In vitro release profiles of the optimized formulations showed an initial burst followed by slow and sustained drug release after 18 h (64.2 ± 3.2%) and 48 h (84.6 ± 4.23%), respectively. Additionally, the CSNPs and CSNP-SSL nanoparticles showed a sustained antibacterial action against Staphylococcus aureus (15.7 ± 0.1 and 19.1 ± 1.2 mm) and Escherichia coli (17.5 ± 0.8 and 21.6 ± 1.7 243 mm). Interestingly, CSNP-SSL showed better capability (89.4 ± 1.2% and 95.8 ± 0.7%) than did CSNPs in inhibiting antibiofilm production by Enterobacter tabaci (E2) and Klebsiella quasipneumoniae (SC3). Therefore, CSNPs are a promising dosage form for sustained drug delivery and enhanced antibacterial and antibiofilm activity of SSL; these results could be translated into increased patient compliance.

Propitious maneuvering for delivery of the phytopharmaceutical "apocynin" to induced fulminant hepatitis in BALB/c mice: In vitro and in vivo assessments

Apocynin (APO), a specific nicotinamide adenine dinucleotide phosphate-oxidase (NADPH-oxidase, NOX) inhibitor, has recently emerged as a bioactive phytochemical with eminent anti-inflammatory and anti-oxidant activities. To our knowledge, no research has been conducted to fabricate a mucoadhesive nanostructured delivery system of APO that targets the liver. Accordingly, chitosan (CS) surface decorated polymeric nanoparticulate delivery system (PNDS) was victoriously fabricated by double emulsion-solvent evaporation method. Herein, a randomized full 33 factorial design was employed to assess the impact of the independently processing parameters (IPPs) namely; (poly(d,l-lactide-co-glycolide) (PLGA) amount (A)), (polyvinyl alcohol (PVA) concentration (B)), and (CS concentration (C)), on different dependently measured attributes (DMAs). The optimal APO-loaded chitosan-coated poly(d,l-lactide-co-glycolide) nanoparticles (APO-loaded CS-coated PLGA NPs) formula (F19) would be extensively appraised through meticulous in vitro-in vivo studies. Crucially, the results revealed that oral pre-treatment with the optimal formula evoked a prodigious in vivo hepatoprotective efficacy against lipopolysaccharide (LPS)/D-(+)-galactosamine (D-GalN) induced fulminant hepatitis (FH) in BALB/c mice when compared with pure APO, uncoated F19, and plain NPs (P NPs) pretreated groups. In conclusion, APO-loaded CS-coated PLGA NPs could be considered as a promising oral mucoadhesive phytopharmaceutical PNDS to open new prospects for therapeutic intervention in inflammatory based liver diseases.

A Fibrinogen-Mimicking, Activated-Platelet-Sensitive Nanocoacervate Enhances Thrombus Targeting and Penetration of Tissue Plasminogen Activator for Effective Thrombolytic Therapy

The development of a fibrinolytic system with long circulation time, high thrombus targeting, efficient thrombus penetration, effective thrombolysis, and minimal hemorrhagic risk remains a major challenge. Herein, inspired by fibrinogen binding to activated platelets in thrombosis, this article reports a fibrinogen-mimicking, activated-platelet-sensitive nanocoacervate to enhance thrombus penetration of tissue plasminogen activator (tPA) for targeted thrombolytic therapy. This biomimetic nanothrombolytic system, denoted as RGD-Chi@tPA, is constructed by "one-pot" coacervation through electrostatic interactions between positively charged arginine-glycine-aspartic acid (RGD)-grafted chitosan (RGD-Chi) and negatively charged tPA. Flow cytometry and confocal laser scanning microscopy measurements show targeting of RGD-Chi@tPA to activated platelets. Controlled tPA release triggered by activated platelets at a thrombus site is demonstrated. Its targeted fibrinolytic and thrombolytic activities are measured in in vitro models. The pharmacokinetic profiles show that RGD-Chi@tPA can significantly prolong circulation time compared to free tPA. In a mouse tail thrombus model, RGD-Chi@tPA displays efficient thrombus targeting and penetration, enabling a complete vascular recanalization as confirmed by the fluorescence imaging, histochemical assay, and laser speckle contrast imager. Consequently, RGD-Chi@tPA induces a substantial enhancement in thrombolysis with minimal hemorrhagic risk compared to free tPA. This simple, effective, and safe platform holds great promise for the development of thrombolytic nanomedicines.

Bioactive functional collagen-oxidized pullulan scaffold loaded with polydatin for treating chronic wounds

Prolonged inflammation, elevated matrix metalloproteinases, hypoxia, decreased vascularization, increased oxidative stress, and bacterial infection are typical signs of chronic non-healing diabetic wounds. Any agent that improves one or all factors could offer enhanced opportunities for better healing of diabetic wounds. In this study, a polyphenol (polydatin) incorporated collagen scaffold was prepared using a biocompatible crosslinker, oxidized pullulan (Col-OxP3-Po), to treat diabetic wounds. The scaffolds were characterized using SEM, FTIR, antioxidant activity, in vitro and in vivo wound healing assay, gene expression, and immunohistopathological studies. Polydatin incorporated scaffold exhibited 75 % antioxidant activity, hemostatic and erythrocyte adhesion properties. FTIR results proved the incorporation of polydatin in the Col-OxP3-Po scaffold. They were also non-toxic to the 3 T3 fibroblasts with a viability of 93 % and good cell attachment. In vivo, normal and diabetic wound healing studies showed that the Col-OxP3-Po scaffold treated group healed on days 16 and 21. The histological and immunohistochemistry analyses of the granulation tissues showed improved epithelialization, angiogenesis and enhanced collagen deposition by modulating TGF-β3 and MMP - 9 gene expressions favorable for better healing. Thus, this scaffold could be a newer treatment strategy for chronic non-healing wounds.

Mucus-Penetrating Alginate-Chitosan Nanoparticles Loaded with Berberine Hydrochloride for Oral Delivery to the Inflammation Site of Ulcerative Colitis

The rectal enemas of berberine hydrochloride (BH) have emerged as one of the most effective strategies in the clinical treatment of ulcerative colitis (UC). However, oral dosages of BH exhibit a poor anti-inflammatory effect of UC, which may attribute to premature absorption of BH by the upper gastrointestinal tract. Moreover, the thick colonic mucus layer obstructs the penetration of the drug, resulting in low bioavailability to the inflammatory site of the colon. The aim of this study was to develop the mucus-penetrating sodium alginate-chitosan nanoparticles (SA-CS NPs) for oral delivery of BH to the site of colonic ulcer lesions. BH-loaded SA-CS NPs were developed through the ionic gelation method and analyzed for physicochemical characteristics, release performance, penetrability, site retention, and therapeutic efficacy. The results showed that the NPs have a particle size of 257 nm with a negative charge, presenting desired pH-dependent release behavior. The permeation studies elucidated that negatively charged SA-CS NPs had 2.9 times higher mucus penetration ability than positively charged CS NPs. An ex vivo retention study indicated the high retention of BH-SA-CS NPs at the colon site for more than 16 h. In vivo therapeutic effectiveness demonstrated that the prepared NPs could not only alleviate colonic injury by decreasing the disease activity index and colon mucosa damage index, but also improve the immunologic function by decreasing the spleen index. In conclusion, the BH-SA-CS NPs could enhance the mucus permeability and deliver drugs to the colonic inflammation site, providing new insights into improving the therapeutic effect of UC.

A different approach to immunochemotherapy for colon Cancer: Development of nanoplexes of cyclodextrins and Interleukin-2 loaded with 5-FU

Immune system deficiencies are crucial in the progression of cancer, predominantly because immune cells are not stimulated by cytokines to eradicate cancer cells. Immunochemotherapy is currently considered an innovative approach that creates pathways in cancer treatment, sometimes also aiding in the efficacy of chemotherapeutics. The aim of this study was to prepare a cyclodextrin (CD) nanoplex based on charge interaction to deliver the anticancer drug 5-fluorouracil (5-FU) and Interleukin-2 (IL-2), thereby forming a nanoscale drug delivery system aimed at chemo-immunotherapy for colorectal cancers. The CD:IL-2 nanoplexes were obtained with a particle size below 100 nm and a cationic surface charge based on the extent of charge interaction of the cationic CD polymer with negatively charged IL-2. The loading capacity of CD nanoplexes was 40% for 5-FU and 99.8% for IL-2. Nanoplexes maintained physical stability in terms of particle size and zeta potential in aqueous solution for 1 week at + 4 °C. Moreover, the structural integrity of IL-2 loaded into CD nanoplexes was confirmed by SDS-PAGE analysis. The cumulative release rates of both 5-FU and IL-2 were found to be more than 80% in simulated biological fluids in 12 h. Cell culture studies demonstrate that CD polymers are safe on healthy L929 mouse fibroblast cells. Drug-loaded CD nanoplexes were determined to have a higher anticancer effect than free drug solution against CT26 mouse colon carcinoma cells. In addition, intestinal permeability studies supported the conclusion that CD nanoplexes could be promising candidates for oral chemotherapy as well. In conclusion, effective cancer therapy utilizing the absorptive/cellular uptake effect of CDs, the synergic effect and co-transport of chemotherapeutic drugs and immunotherapeutic molecules is a promising approach. Furthermore, the transport of IL-2 with this nano-sized system can reduce or avoid its toxicity problem in the clinic.

Developed meloxicam loaded microparticles for colon targeted delivery: Statistical optimization, physicochemical characterization, and in-vivo toxicity study

The study aimed to fabricate and evaluate Meloxicam (MLX) loaded Hydroxypropyl Methylcellulose (HPMC) microparticles for colon targeting because MLX is a potent analgesic used in the treatment of pain and inflammation associated with colorectal cancer (CRC). Nevertheless, its efficiency is limited by poor solubility and gastrointestinal tracts (GIT) associated side effects. Seventeen formulations of MLX loaded HPMC microparticles were fabricated by the oil-in-oil (O/O)/ emulsion solvent evaporation (ESE) technique. A 3-factor, 3-level Box Behnken (BBD) statistical design was used to estimate the combined effects of the independent variables on the dependent variables (responses), such as the percent yield (R1), the entrapment efficiency (EE) (R2), mean particle size (R3) and in vitro percentage of cumulative drug release (R4). For physicochemical characterization FTIR, XRD, DSC, and SEM analyses were performed. Biocompatibility and non-toxicity were confirmed by in-vivo acute oral toxicity determination. The percentage yield and EE were 65.75-90.71%, and 70.62-88.37%, respectively. However, the mean particle size was 62.89-284.55 μm, and the in vitro cumulative drug release percentage was 74.25-92.64% for 24 hours. FTIR analysis showed that the composition of the particles was completely compatible, while XRD analysis confirmed the crystalline nature of the pure drug and its transition into an amorphous state after formulation. DSC analysis revealed the thermal stability of the formulations. The SEM analysis showed dense spherical particles. The toxicity study in albino rabbits showed no toxicity and was found biocompatible. The histopathological evaluation showed no signs of altered patterns. Results of this study highlighted a standard colonic drug delivery system with the ability to improve patient adherence and reduce GIT drug-associated side effects in CRC treatment.

Brij Niosomes as Carriers for Sustained Drug Delivery─A Fluorescence-Based Approach to Probe the Niosomal Microenvironment

Niosomes were prepared using a triad of polyoxyethylene alkyl ether surfactants. The focus was to elucidate the effects of varying alkyl chain length and varying hydrophilic headgroups on the structure of the niosomes, with an aim to design niosomes for efficient encapsulation and release of both hydrophobic and hydrophilic drugs. The phase transitions of the surfactants were ascertained by differential scanning calorimetry. It was found that the headgroup has a profound influence on the niosomal bilayer. Fluorescent probes Coumarin 153 (C-153) and 1,6-diphenyl-1,3,5-hexatriene were used to probe the structural integrity of the niosomal bilayer under stress conditions. Other aspects of the niosomes were probed by following the aggregation of the dyes fluorescein (FL) and Nile Red, red edge excitation shift, and fluorescence resonance energy transfer (FRET) between them. Fluorescence lifetime imaging microscopy provides proof of the exact location of the donor and acceptor dyes in the niosomes under FRET condition. It was also shown that the niosomes are efficient "carriers" for entrapment and controlled release of the chemotherapeutic drug 5-fluorouracil. It was found that a rigid niosomal bilayer leads to controlled drug release. The present work is relevant for the future use of these niosomes for cargo entrapment.

Preparation and characterization of magnetic nanohydrogel based on chitosan for 5-fluorouracil drug delivery and kinetic study

Chemotherapy is currently used for most cancer treatments, but one of the significant problems of this treatment is that it affects the healthy tissues of the body. Therefore, designing new systems for the intelligent and controlled release of these drugs in cancer tissues is one of the major challenges in the world. Hence, today, huge costs are spent designing appropriate new drug delivery systems (DDS) with controlled drug release. In this study, chitosan-polyacrylic acid encapsulated Fe₃O₄ magnetic nanogelic core-shell (Fe₃O₄@CS-PAA) was synthesized in the presence of glutaraldehyde used for loaded anticancer 5-fluorouracil (5-FU) drug. Also, the prepared Fe₃O₄@CS-PAA was characterized by using FT-IR, SEM, XRD, and VSM analysis. Then, drug delivery tests were carried out in the in-vitro conditions that are the simulated physiological environment and tumor tissue conditions. The drug release tests indicated that the Fe₃O₄@CS-PAA upgraded the rate of 5-FU release from nanogelic core-shell under tumor tissue conditions (pH 4.5) than physiological environments (pH 7.4). In addition, various models were used to investigate the drug release mechanism. Results of modeling studies of drug release showed the mechanism of 5-FU release from Fe₃O₄@CS-PAA controlled by Fickian diffusion.

Insight into the Loading Properties of Na+ Green-Functionalized Clinoptilolite as a Potential Carrier for the 5-Fluorouracil Drug, its Release Kinetics, and Cytotoxicity

Herein, natural zeolite (clinoptilolite) was functionalized by Na⁺ ions (G.Na⁺/Clino) utilizing a green tea extract prepared by a green production method as a potential carrier for the 5-fluorouracil (5-Fu) drug with enhanced physicochemical behaviors. The G.Na⁺/Clino-modified product showed enhanced surface area (312 m²/g) and ion-exchange capacity (387 mequiv/100 g). The loading studies reflect high and controlled loading properties of G.Na⁺/Clino with an actual loading capacity of 291 and 462 mg/g, respectively. The loading reactions of 5-Fu into G.Na⁺/Clino were of pseudo-second-order kinetics and exhibited Langmuir isotherm properties. This suggested a monolayer and homogeneous loading process by chemical complexation and ion-exchange mechanisms with a Gaussian energy value of 10.47 kJ/mol. Additionally, these reactions were of endothermic and spontaneous nature based on the determined thermodynamic parameters. The release studies demonstrated the 5-Fu release profile for about 150 h at pH 1.2 and for 80 h at pH 7.4. The release reactions had non-Fickian transport properties and were controlled by both erosion and diffusion mechanisms, considering the release kinetic findings and the values of the diffusion exponent (0.42 at pH 1.2 and 0.37 at pH 7.4). The composite showed remarkable biocompatibility based on the measured cell viability and a cytotoxic effect on normal colorectal cells (CCD-18Co). Additionally, the application of G.Na⁺/Clino as an inorganic carrier for the 5-Fu drug prompted the cytotoxic effect of the drug on colon cancer cell treatment (HCT-116).

Effectiveness of 5-Fluorouracil and gemcitabine hydrochloride loaded iron‑based chitosan-coated MIL-100 composite as an advanced, biocompatible, pH-sensitive and smart drug delivery system on breast cancer therapy

This study was planned to evolve the bioavailability and therapeutic efficiency of Gemcitabine (GEM) and 5-Fluorouracil with decreased side effects using MIL-100 nano-composite as carrier. Impregnation approach was used for encapsulation of 5-Fluorouracil alone and with GEM inside the MIL-100. The formed 5-Fluorouracil@MIL-100 and 5-Fluorouracil-GEM@MIL-100 were then coated with chitosan, sequentially chelated with iron(III) and conjugated with quercetin, eventually obtaining a multifunctional MIL-100 nanocarrier. The hybrid nanocarrier nascency was verified by different characterization results. pH-sensitive releases of 5-Fluorouracil and GEM were observed because of the inherent pH-dependent stability of MIL-100. Additionally, we evaluated the anti-cancer activity of these nanocarriers through WST-1 analysis and acridine orange staining in MCF-7 human breast cancer and HUVEC control cell lines. Our findings showed that all nanocarriers exhibited anti-cancer activity and induced apoptosis in MCF-7 cells. However, 5-Fluorouracil@MIL-100 and chitosan-coated 5-Fluorouracil@MIL-100 with quercetin were more effective than other nanocarriers in MCF-7 cells (p < 0.05). Moreover, we observed cytotoxicity in HUVEC cells due to the adverse side effects of chemotherapy drugs. However, chitosan coated nanocarriers with quercetin were less toxic on HUVEC cells at particularly 1 µg/mL. Therefore, MIL-100 could be used for a promising chemotherapeutic drugs delivery and chitosan coated drugs with quercetin could be useful for reducing toxicity on normal cells.

Preparation of Ligand Brush Nanocapsules for Robust Self-Controlled Antimicrobial Activity with Low Cytotoxicity at Target pH and Humidity

This study prepared nanocapsules (NCs) with excellent self-controlled antimicrobial activity at pH 6–7 and humidity 45–100%, conditions in which most bacterial and fungal strains thrive. The nanocapsule substrate (NC@SiO₂) was 676 nm in diameter, and the ligand-grafted capsule (NC@SiO₂-g-MAA) was 888 nm. The large surface area and outer ligand brush of the NCs induced a rapid, self-controlled antibacterial response in the pH and humidity conditions needed for industrial and medical applications. Ligand-brush NCs containing an anionic antimicrobial drug had a rapid release effect because of the repellent electrostatic force and swelling properties of the ligand brushes. Controlled release of the drug was achieved at pH 6 and humidity of 45% and 100%. As many carboxylic acid groups are deprotonated into carboxylic acids at pH 5, the NC@SiO₂-g-MAA had a high negative charge density. Carboxylic acid groups are anionized (–COO⁻) at pH 6 and above and push each other out of the capsule, expanding the outer shell as in a polymer brush to create the release behavior. The surface potential of the NC intermediate (NC@SiO₂-MPS) was −23.45 [mV], and the potential of the capsule surface decreased to −36.4 [mV] when the MAA ligand brushes were grafted onto the surface of the capsule intermediate. In an antimicrobial experiment using Escherichia coli, a clear zone of 13–20 mm formed at pH 6, and the E. coli was eradicated completely at pH 6 and pH 7 when the humidity was 100%.

A novel combination therapy for multidrug resistant pathogens using chitosan nanoparticles loaded with β-lactam antibiotics and β-lactamase inhibitors

Antimicrobial resistance is one of the greatest global threats. Particularly, multidrug resistant extended-spectrum β-lactamase (ESBL)-producing pathogens confer resistance to many commonly used medically important antibiotics, especially beta-lactam antibiotics. Here, we developed an innovative combination approach to therapy for multidrug resistant pathogens by encapsulating cephalosporin antibiotics and β-lactamase inhibitors with chitosan nanoparticles (CNAIs). The four combinations of CNAIs including two cephalosporin antibiotics (cefotaxime and ceftiofur) with two β-lactamase inhibitors (tazobactam and clavulanate) were engineered as water-oil-water emulsions. Four combinations of CNAIs showed efficient antimicrobial activity against multidrug resistant ESBL-producing Enterobacteriaceae. The CNAIs showed enhanced antimicrobial activity compared to naïve chitosan nanoparticles and to the combination of cephalosporin antibiotics and β-lactamase inhibitors. Furthermore, CNAIs attached on the bacterial surface changed the permeability to the outer membrane, resulting in cell damage that leads to cell death. Taken together, CNAIs have provided promising potential for treatment of diseases caused by critically important ESBL-producing multidrug resistant pathogens.

Litchi chinensis inspired nanoformulations: a synergy guided approach for unraveling promising cytotoxic attributes of metal and nonmetal conjugates

In present study, diverse Litchi chinensis-mediated nanostructures in combination with 5-fluorouracil drug were fabricated viz. Au, Se, Ag, Ag-Se, Ag-Au, 5-FU Ag-Se and 5-FU Ag-Au with subsequent characterization and scrutinization of their anticarcinogenic capabilities. UV-Visible spectroscopic analysis confirmed the state transition for each precursor salt. XRD and transmission electron microscopy analysis revealed spherical/quasispherical nanostructures with monoclinic crystalline organization ranged between 18 nm and 38 nm. FTIR analysis revealed fabricated nanoparticles to be capped with various phytoconstituents. DLS and Zeta potential analysis of unloaded and drug-loaded bielemental nanoparticles (BNPs) showed comparatively large hydrodynamic particle size distribution and sufficient stability of nanoparticles. BNPs showed promising lethality concentrations for brine shrimp (LC50 < 2 μg/ml) and antitumor (LC50 < 10 μg/ml) assessments. These findings were in positive correlation with the antioxidant inhibitory concentrations IC50 (74.2-180.1 μg/ml) of the tested entities. Ag-Se and Ag-Au were loaded with 5-FU (loading efficiency of 47% ± 1.14 and 25% ± 0.32, respectively) in light of their promising cytotoxic actions. All nanostructures showed profound hemocompatibility with maximum hemolytic activity as low as 2.4%. Highly significant difference (P < 0.01) was observed in antineoplastic potentials of unloaded and 5-FU loaded BNPs against HepG2 and HT144, with most substantial IC50 for 5-FU Ag-Au (8.95 ± 2.86 μg/ml). 5-FU Ag-Au was identified as a significant inducer of DNA fragmentation with maximum relative tail moment (HepG2: 3.45 ± 0.21) among all treatments.

Fabrication of moxifloxacin HCl-loaded biodegradable chitosan nanoparticles for potential antibacterial and accelerated cutaneous wound healing efficacy

AIM

This work aims to formulate topical hybrid gel containing chitosan-coated moxifloxacin (MXF) HCl nanoparticles (NPs) with enhanced antibacterial and healing activity.

METHODS

MXF HCl NPs prepared by the ionic gelation method were loaded onto a hybrid chitosan carbomer gel. Size analysis of the prepared NPs was performed using SEM and Zeta-sizer. Further characterisation was done using Fourier transforms infra-red spectroscopy (FTIR), X-ray diffraction (XRD), and Thermogravimetric analysis (TGA). Prepared gel was evaluated for its in vitro drug release, biocompatibility, antibacterial activity, and stability studies under storage conditions. In-vivo wound healing was measured by observing percentage reduction in wound.

RESULTS

NPs have 359 ± 79 nm mean particle size, 31.01 mV zeta potential with 0.008 polydispersity index (PD1), 63.5% drug entrapment and 83 ± 3.5% drug release at pH 5.5. Hybrid chitosan carbomer gel showed good biocompatibility, antibacterial, in-vivo wound healing properties and stable properties.

CONCLUSIONS

NP-loaded hybrid gel can be an effective treatment for acute and challenged topical wounds.

Insight into the Technical Qualification of the Sonocogreen CaO/Clinoptilolite Nanocomposite (CaO(NP)/Clino) as an Advanced Delivery System for 5-Fluorouracil: Equilibrium and Cytotoxicity

Clinoptilolite as a natural zeolite was integrated with green CaO nanoparticles forming the green nanocomposite CaO_(NP)/Clino. The CaO_(NP)/Clino composite was assessed as a potential carrier for 5-fluorouracil (5-FL) drug. The CaO_(NP)/Clino carrier achieved an enhanced 5-FL loading capacity of 305.3 mg/g as compared to 163 mg/g for pure clinoptilolite. The kinetics of the 5-FL loading follow the properties of the pseudo-first-order model, while the equilibrium results are related to the Langmuir isotherm. Therefore, the 5-FL loading processes occurred in the monolayer formed by homogeneous active loading receptors on the surface of the CaO_(NP)/Clino carrier. The Gaussian energy of the 5-FL loading reaction (9.2 KJ/mol) reflected the dominant effect for the chemical mechanisms, especially the zeolitic ion-exchange mechanisms. Additionally, the thermodynamic parameters suggested endothermic, feasible, and spontaneous properties for the occurred 5-FL loading reactions. The release profile of 5-FL from CaO_(NP)/Clino has continuous and long properties (150 h) at pH 1.2 (gastric fluid) and pH 7.4 (intestinal fluid). The kinetic studies of the release reactions show considerable agreement with Higuchi, Hixson-Crowell, and Korsmeyer-Peppas models. Such high fitting results and the diffusion exponent values (0.49 at pH 1.2 and 0.48 at pH 7.4) reflected the release properties of the Fickian transport behavior involving complex erosion and diffusion mechanisms. The cytotoxicity study of CaO_(NP)/Clino on colorectal normal cells (CCD-18Co) declare the safe and biocompatible effect as a carrier for the 5-FL drug. Additionally, CaO_(NP)/Clino as a carrier causes considerable enhancement for the cytotoxic effect of the loaded 5-FL drug on colon cancer cells (HCT-116).

Intranasal delivery of phenytoin-loaded nanoparticles to the brain suppresses pentylenetetrazol-induced generalized tonic clonic seizures in an epilepsy mouse model

In this work we describe the preparation and characterization of lecithin-chitosan nanoparticles (L₁₀C_i⁺), and investigate their ability to deliver the anti-epileptic drug phenytoin (PHT) to mouse brain following intranasal (IN) administration. L₁₀C_i⁺ were retained in the nasal cavity compared to PHT in PEG200 solution (PHT/PEG), which suffered immediate nasal drainage. PHT was detected in the brain after 5 min of IN administration reaching a maximum of 11.84 ± 2.31 %ID g^-1 after 48 hours. L₁₀C_i⁺ were associated with a higher brain/plasma ratio (C_b/p) compared to the experimental control comprising free PHT injected via the intraperitoneal route (PHT-IP) across all tested time points. Additionally, L₁₀C_i⁺ led to lower PHT accumulation in the liver and spleen compared to PHT-IP, which is vital for lowering the systemic side effects of PHT. The relatively high drug targeting efficiency (DTE%) of 315.46% and the drug targeting percentage (DTP%) of 68.29%, combined with the increasing anterior-to-posterior gradient of PHT in the brain confirmed the direct nose-to-brain transport of PHT from L₁₀C_i⁺. Electroencephalogram (EEG) analysis was used to monitor seizure progression. L₁₀C_i⁺ resulted in a complete seizure suppression after 4 hours of administration, and this inhibition persisted even with an 8-fold reduction of the encapsulated dose compared to the required PHT-IP dose to achieve a similar inhibitory effect due to systemic loss. The presented findings confirm the possibility of using L₁₀C_i⁺ as a non-invasive delivery system of PHT for the management of epilepsy using reduced doses of PHT.