Low Molecular Weight Chitosan-Coated PLGA Nanoparticles for Pulmonary Delivery of Tobramycin for Cystic Fibrosis

Chitosan-coated nanoparticles in innovative cancer bio-medicine

In the recent decade, nanoparticles (NPs) have had enormous implications in cancer biomedicine, including research, diagnosis, and therapy. However, their broad application still faces obstacles due to some practical limitations and requires further development. Recently, there has been more interest in the coated class of nanoparticles to address those challenges. Chitosan-coated NPs are simple to produce, biodegradable, biocompatible, exhibit antibacterial activity, and have less cytotoxicity. This study provides an updated and comprehensive overview of the application of chitosan-coated NPs as a promising class of NPs in cancer biomedicine. Additionally, we discussed chitosan-coated lipid, metal, and polymer-based nanoparticles in biomedical applications. Furthermore, different coating methods and production/characterization procedures were reviewed. Moreover, the biological and physicochemical advantages of chitosan-coated NPs, including facilitated controlled release, greater physicochemical stability, improved cell/tissue interaction, and enhanced bioavailability of medications, were highlighted. Finally, the prospects of chitosan-coated NPs in cancer biomedicine were discussed.

Nanostructured lipid carriers (NLCs): A promising candidate for lung cancer targeting

Lung cancer stands as the foremost health issue and the principal reason for mortality worldwide. It is projected that India will see over 1.73 million new cases and more than 880,000 deaths related to cancer, with lung cancer being a significant contributor. The efficiency of existing chemotherapy procedures is not optimal because of less soluble nature and short half-life of anticancer substances. More precipitated toxicity and non-existence of targeting propensity can lead to severe side effects, non-compliance, and inconvenience for patients. Nonetheless, the domain of nanomedicine has undergone a revolution in the past few years with the advent of novel drug delivery mechanisms that tackle the drawbacks of conventional approaches. Diverse nanoparticle-based drug delivery methods, including liposomes, nanoparticles, nanostructured lipid carrier and solid lipid nanoparticle that encapsulated chemotherapy drugs, are currently employed for efficient lung cancer therapy. NLCs, recognized as the second-generation lipid nanocarriers, are a focused drug delivery mechanism that has garnered significant interest owing to their multitude of advantages such as increased stability, minimal toxicity, prolonged shelf life, superior encapsulation capability, and biocompatible nature. This review focuses on the NLCs carrier system, discussing its preparation methods, types, characterization, applications, and future prospects in lung cancer treatment.

Zein nanoparticles containing ceftazidime and tobramycin: antibacterial activity against Gram-negative bacteria

Aims: This work describes the encapsulation of ceftazidime and tobramycin in zein nanoparticles (ZNPs) and the characterization of their antibacterial and antibiofilm activities against Gram-negative bacteria. Materials & methods: ZNPs were synthesized by nanoprecipitation. Cytotoxicity was assessed by MTT assay and antibacterial and antibiofilm assays were performed by broth microdilution and violet crystal techniques. Results: ZNPs containing ceftazidime (CAZ-ZNPs) and tobramycin (TOB-ZNPs) showed drug encapsulation and thermal stability. Encapsulation of the drugs reduced their cytotoxicity 9-25-fold. Antibacterial activity, inhibition and eradication of biofilm by CAZ-ZNPs and TOB-ZNPs were observed. There was potentiation when CAZ-ZNPs and TOB-ZNPs were combined. Conclusion: CAZ-ZNPs and TOB-ZNPs present ideal physical characteristics for in vivo studies of antibacterial and antibiofilm activities.

Competitive inhibition of nicotine acetylcholine receptors using microneedles of nicotine and varenicline for smoking withdrawal therapy

Current strategies for smoking withdrawal conditions involve monotherapy of nicotine and combinational therapy of nicotine with varenicline or bupropion as per the CDC and FDA. The available dosage forms for nicotine are patches, gums, inhalers and nasal sprays, bupropion and varenicline are available in tablet form. This research work focused on developing a microneedle delivery system to deliver combination drug for overcoming the obstacles encountered by oral route of administration of varenicline such as severe side effects (mood swings, agitation, depressed behaviour, seizures, etc), and nicotine therapy challenges such as short half-life, repeated dosing, nausea, and vomiting. The nanoparticles of nicotine prepared by nanoprecipitation method showed particle size PTZ (356.6 ± 65.98), percentage entrapment efficiency (35.55 % ± 0.007), in-vitro drug release (47.89 % ± 0.7) for 72 h. Microneedles showed height (600 μm), width (350 μm), and tip diameter (10 μm). The nanoparticles encapsulated in microneedles showed in-vitro sustained delivery of nicotine (67.00 % ± 4.92) and varenicline (79.78 % ± 1.09) in 48 h. Nicotine released in a sustained manner attaches to the nicotine acetylcholine receptors (nAchR) to release dopamine for controlling the withdrawal challenges such as anxiety, irritability, cravings, disturbed sleep pattern, etc. The varenicline released from microneedles binds to the nAchR and inhibits dopamine release responsible for the euphoric effect induced by nicotine, and thus assists in curbing the nicotine withdrawal symptoms. This combination microneedle system offers prolonged treatment in a single application for smoking withdrawal conditions wherein patients are not in stage of oral dosing because of repeated dosing resulting in adverse effects like seizures, hypertension, sleep disturbances, insomnia, and nausea.

Tobramycin-loaded nanoparticles of thiolated chitosan for ocular drug delivery: Preparation, mucoadhesion and pharmacokinetic evaluation

The present work aimed to develop nanoparticles of tobramycin (TRM) using thiolated chitosan (TCS) in order to improve the mucoadhesion, antibacterial effect and pharmacokinetics. The nanoparticles were evaluated for their compatibility, thermal stability, particle size, zeta potential, mucoadhesion, drug release, kinetics of TRM release, corneal permeation, toxicity and ocular irritation. The thiolation of chitosan was confirmed by 1H NMR and FTIR, which showed peaks at 6.6 ppm and 1230 cm-1, respectively. The nanoparticles had a diameter of 73 nm, a negative zeta potential (-21 mV) and a polydispersity index of 0.15. The optimized formulation, NT8, exhibited the highest values of mucoadhesion (7.8 ± 0.541h), drug loading (87.45 ± 1.309%), entrapment efficiency (92.34 ± 2.671%), TRM release (>90%) and corneal permeation (85.56%). The release pattern of TRM from the developed formulations was fickian diffusion. TRM-loaded nanoparticles showed good antibacterial activity against Pseudomonas aeruginosa. The optimized formulation NT8 (0.1% TRM) greatly increased the AUC(0-∞) (1.5-fold) while significantly reducing the clearance (5-fold) compared to 0.3% TRM. Pharmacokinetic parameters indicated improved ocular retention and bioavailability of TRM loaded nanoparticles. Our study demonstrated that the TRM-loaded nanoparticles had improved mucoadhesion and pharmacokinetics and a suitable candidate for effective treatment of ocular bacterial infections.

Modeling of Chitosan modified PLGA atorvastatin-curcumin conjugate (AT-CU) nanoparticles, overcoming the barriers associated with PLGA: an approach for better management of atherosclerosis

Conjugate drugs are evolving into potent techniques in the drug development process for enhancing the biopharmaceutical, physicochemical, and pharmacokinetic properties. Atorvastatin (AT) is the first line of treatment for coronary atherosclerosis; however its therapeutic efficacy is limited because of its poor solubility and fast pass metabolism. Curcumin (CU) is evidenced in several crucial signaling pathways linked to lipid regulation and inflammation. To enhance the therapeutic efficacy and physical properties of AT and CU, a new conjugate derivative (AT-CU) was synthesized and assessed by in silico, in vitro characterizations, and in vivo efficacy through mice model. Although the biocompatibility and biodegradability of Polylactic-co-Glycolic Acid (PLGA) in nanoparticles are well documented, burst release is a common issue with this polymer. Hence the current work used chitosan as a drug release modifier to the PLGA nanoparticles. The chitosan-modified PLGA AT-CU nanoparticles were prepaid by single emulsion and solvent evaporation technique. With raising the concentration of chitosan the particle size grew from 139.2 nm to 197.7 nm, the zeta potential rose from -20.57 mV to 28.32 mV, and the drug encapsulation efficiency improved from 71.81 % to 90.57 %. At 18 hours, the burst release of AT-CU from PLGA nanoparticles was seen, hitting abruptly 70.8%. For chitosan-modified PLGA nanoparticles, the burst release pattern was significantly reduced which could be due to the adsorption of the drug on the surface of chitosan. The efficiency of the ideal formulation i.e F4 (chitosan/PLGA= 0.4) in treating atherosclerosis was further strongly evidenced by in vivo investigation.

Design of Chitosan-Coated, Quercetin-Loaded PLGA Nanoparticles for Enhanced PSMA-Specific Activity on LnCap Prostate Cancer Cells

Nanoparticles are designed to entrap drugs at a high concentration, escape clearance by the immune system, be selectively taken up by cancer cells, and release bioactives in a rate-modulated manner. In this study, quercetin-loaded PLGA nanoparticles were prepared and optimized to determine whether coating with chitosan would increase the cellular uptake of the nanoparticles and if the targeting ability of folic acid as a ligand can provide selective toxicity and enhanced uptake in model LnCap prostate cancer cells, which express high levels of the receptor prostate-specific membrane antigen (PSMA), compared to PC-3 cells, that have relatively low PSMA expression. A design of experiments approach was used to optimize the PLGA nanoparticles to have the maximum quercetin loading, optimal cationic charge, and folic acid coating. We examined the in vitro release of quercetin and comparative cytotoxicity and cellular uptake of the optimized PLGA nanoparticles and revealed that the targeted nano-system provided sustained, pH-dependent quercetin release, and higher cytotoxicity and cellular uptake, compared to the non-targeted nano-system on LnCap cells. There was no significant difference in the cytotoxicity or cellular uptake between the targeted and non-targeted nano-systems on PC-3 cells (featured by low levels of PSMA), pointing to a PSMA-specific mechanism of action of the targeted nano-system. The findings suggest that the nano-system can be used as an efficient nanocarrier for the targeted delivery and release of quercetin (and other similar chemotherapeutics) against prostate cancer cells.

Novel Chitosan Nanoparticles Loaded with Methotrexate for Topical Treatment of Psoriasis

AIMS

In this work, CS NPs were prepared by the ionic gelation method and encapsulated with MTX to treat psoriasis dermally.

BACKGROUND

A major drawback of using MTX to treat psoriasis is its limited diffusion through the skin, which may cause insufficient penetration of MTX into the basal layer of the epidermis, where psoriatic cells are generated.

OBJECTIVE

Nanoparticles have been used to enhance MTX diffusion through the skin. The system prepared in this work is expected to direct the drug to psoriasis cells by enhancing the drug diffusion through the skin, which will increase the amount of the drug reaching the epidermis. This is expected to enhance the effectiveness of the drug and to decrease its systemic side effects.

METHODS

Five formulations of Chitosan nanoparticles were prepared and loaded with Methotrexate using the ionic gelation technique. Particle size, dispersity, charge, loading capacity and encapsulation efficacy were measured. Characterization of prepared nanoparticles was conducted to confirm the formation of CS-NPs, successful encapsulation of MTX and its compatibility with other formulation components. In vitro drug release from CS-NPs, its permeation and accumulation in rats' skin were explored. Finally, the anti-psoriatic activity was assessed using the "mouse tail model."

RESULTS

The results showed that the sizes ranged from 132.13 ± 0.70 to 300.60 ± 4.81 nm, where SEM demonstrated the spherical and uniform distribution of the NPs. The surface charge of all NPs was highly positive and ranged from 20.22 ± 1.10 to 30.90 ± 0.70 mV. Further, the EE% and LC% of the nanoparticles were in the range of 77.72%-92.70% and 17.90%-21.81%, respectively. in vitro, the release of methotrexate from the nanoparticles was sustained. Additionally, both the permeation and retention of drugs within the skin were enhanced significantly using this system. Eventually, orthokeratosis% and drug activity% showed significant superiority of MTX-CS NPs over the free drug in treating psoriasis in model mice.

CONCLUSION

In conclusion, MTX-CS NPs can be used to enhance the treatment of psoriasis topically.

Emerging strategies in nanotechnology to treat respiratory tract infections: realizing current trends for future clinical perspectives

A boom in respiratory tract infection cases has inflicted a socio-economic burden on the healthcare system worldwide, especially in developing countries. Limited alternative therapeutic options have posed a major threat to human health. Nanotechnology has brought an immense breakthrough in the pharmaceutical industry in a jiffy. The vast applications of nanotechnology ranging from early diagnosis to treatment strategies are employed for respiratory tract infections. The research avenues explored a multitude of nanosystems for effective drug delivery to the target site and combating the issues laid through multidrug resistance and protective niches of the bacteria. In this review a brief introduction to respiratory diseases and multifaceted barriers imposed by bacterial infections are enlightened. The manuscript reviewed different nanosystems, i.e. liposomes, solid lipid nanoparticles, polymeric nanoparticles, dendrimers, nanogels, and metallic (gold and silver) which enhanced bactericidal effects, prevented biofilm formation, improved mucus penetration, and site-specific delivery. Moreover, most of the nanotechnology-based recent research is in a preclinical and clinical experimental stage and safety assessment is still challenging.

Recent advancements and perspective of ciprofloxacin-based antimicrobial polymers

In recent years, microbial pathogens, which are major sources of infections, have become a widespread concern across the world. The number of deaths caused by infectious diseases is continually rising, according to World Health Organization records. Antimicrobial resistance, particularly resistance to several drugs, is steadily growing in percentages of organisms. Ciprofloxacin is a second-generation fluoroquinolone with significant antimicrobial activity and pharmacokinetic characteristics. According to studies, many bacteria are resistant to the antibiotic ciprofloxacin. In this article, we look into polymers as ciprofloxacin macromolecular carriers with a wide range of antibacterial activity. We also discuss the latter form of coupling, in which ciprofloxacin and polymers are covalently bonded. This article also discusses the use of antimicrobial polymers in combination with ciprofloxacin in a various sectors. The current review article provides an overview of publications in the last five years on polymer loaded or modified with ciprofloxacin having applications in numerous sectors.

Polymeric Nanoparticles for Inhaled Vaccines

Many recent studies focus on the pulmonary delivery of vaccines as it is needle-free, safe, and effective. Inhaled vaccines enhance systemic and mucosal immunization but still faces many limitations that can be resolved using polymeric nanoparticles (PNPs). This review focuses on the use of properties of PNPs, specifically chitosan and PLGA to be used in the delivery of vaccines by inhalation. It also aims to highlight that PNPs have adjuvant properties by themselves that induce cellular and humeral immunogenicity. Further, different factors influence the behavior of PNP in vivo such as size, morphology, and charge are discussed. Finally, some of the primary challenges facing PNPs are reviewed including formulation instability, reproducibility, device-related factors, patient-related factors, and industrial-level scale-up. Herein, the most important variables of PNPs that shall be defined in any PNPs to be used for pulmonary delivery are defined. Further, this study focuses on the most popular polymers used for this purpose.

Microfluidic-Based Formulation of Essential Oils-Loaded Chitosan Coated PLGA Particles Enhances Their Bioavailability and Nematocidal Activity

In this study, poly (lactic-co-glycolic) acid (PLGA) particles were synthesized and coated with chitosan. Three essential oil (EO) components (eugenol, linalool, and geraniol) were entrapped inside these PLGA particles by using the continuous flow-focusing microfluidic method and a partially water-miscible solvent mixture (dichloromethane: acetone mixture (1:10)). Encapsulation of EO components in PLGA particles was confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction, with encapsulation efficiencies 95.14%, 79.68%, and 71.34% and loading capacities 8.88%, 8.38%, and 5.65% in particles entrapped with eugenol, linalool, and geraniol, respectively. The EO components’ dissociation from the loaded particles exhibited an initial burst release in the first 8 h followed by a sustained release phase at significantly slower rates from the coated particles, extending beyond 5 days. The EO components encapsulated in chitosan coated particles up to 5 μg/mL were not cytotoxic to bovine gut cell line (FFKD-1-R) and had no adverse effect on cell growth and membrane integrity compared with free EO components or uncoated particles. Chitosan coated PLGA particles loaded with combined EO components (10 µg/mL) significantly inhibited the motility of the larval stage of Haemonchus contortus and Trichostrongylus axei by 76.9%, and completely inhibited the motility of adult worms (p < 0.05). This nematocidal effect was accompanied by considerable cuticular damage in the treated worms, reflecting a synergistic effect of the combined EO components and an additive effect of chitosan. These results show that encapsulation of EO components, with a potent anthelmintic activity, in chitosan coated PLGA particles improve the bioavailability and efficacy of EO components against ovine gastrointestinal nematodes.

Neutralization of ionic interactions by dextran-based single-chain nanoparticles improves tobramycin diffusion into a mature biofilm

The extracellular matrix protects biofilm cells by reducing diffusion of antimicrobials. Tobramycin is an antibiotic used extensively to treat P. aeruginosa biofilms, but it is sequestered in the biofilm periphery by the extracellular negative charge matrix and loses its efficacy significantly. Dispersal of the biofilm extracellular matrix with enzymes such as DNase I is another promising therapy that enhances antibiotic diffusion into the biofilm. Here, we combine the charge neutralization of tobramycin provided by dextran-based single-chain polymer nanoparticles (SCPNs) together with DNase I to break the biofilm matrix. Our study demonstrates that the SCPNs improve the activity of tobramycin and DNase I by neutralizing the ionic interactions that keep this antibiotic in the biofilm periphery. Moreover, the detailed effects and interactions of nanoformulations with extracellular matrix components were revealed through time-lapse imaging of the P. aeruginosa biofilms by laser scanning confocal microscopy with specific labeling of the different biofilm components.

Chitosan-based biomaterials for the treatment of bone disorders

Bone is an alive and dynamic organ that is well-differentiated and originated from mesenchymal tissues. Bone undergoes continuous remodeling during the lifetime of an individual. Although knowledge regarding bones and their disorders has been constantly growing, much attention has been devoted to effective treatments that can be used, both from materials and medical performance points of view. Polymers derived from natural sources, for example polysaccharides, are generally biocompatible and are therefore considered excellent candidates for various biomedical applications. This review outlines the development of chitosan-based biomaterials for the treatment of bone disorders including bone fracture, osteoporosis, osteoarthritis, arthritis rheumatoid, and osteosarcoma. Different examples of chitosan-based formulations in the form of gels, micro/nanoparticles, and films are discussed herein. The work also reviews recent patents and important developments related to the use of chitosan in the treatment of bone disorders. Although most of the cited research was accomplished before reaching the clinical application level, this manuscript summarizes the latest achievements within chitosan-based biomaterials used for the treatment of bone disorders and provides perspectives for future scientific activities.

Oxidized Chitosan-Tobramycin (OCS-TOB) Submicro-Fibers for Biomedical Applications

Chitosan (CS) is a biodegradable, biocompatible, and non-toxic natural amino-poly-saccharide with antibacterial ability, owing to its positively charged amino groups. However, the low charge density leads to poor antibacterial efficiency which cannot meet the biomedical application requirements. In this study, Tobramycin (TOB) was grafted onto the backbone of oxidized chitosan (OCS) to synthesize oxidized chitosan-tobramycin (OCS-TOB). FTIR, ¹H NMR and elemental analysis results demonstrated that OCS-TOB was successfully synthesized. OCS-TOB/PEO composite fibrous materials were produced by a self-made centrifugal spinning machine. In vitro experiments showed that cells proliferated on the submicro-fibrous OCS-TOB/PEO of appropriate concentration, and the antibacterial ability of OCS-TOB was much improved, compared with pristine CS. The results demonstrated that OCS-TOB/PEO nanofibrous materials could potentially be used for biomedical applications.

Photolytic Controlled Release Formulation of Methotrexate Loaded in Chitosan/TiO2 Nanoparticles for Breast Cancer

A new system composed of chitosan nanoparticles loaded with methotrexate (MTX-CS-NPs) and functionalized with photocatalytic TiO₂ nanoparticles (TiO₂-NPs) was prepared. This system is expected to initiate polymeric rupture of MTX-CS-NPs and subsequently release MTX, upon illumination with UV light. MTX-CS-NPs were prepared and characterized in terms of particle size, charge, polydispersity and drug release before and after coating with TiO₂-NPs. The release of MTX in vitro was studied in dark, light and UV light. Finally, coated and uncoated MTX-CS-NPs were studied in vitro using MCF-7 cell line. The functionalized NPs were larger in size, more polydisperse and carried higher positive charges compared to the unfunctionalized NPs. The entrapment efficacy was high reaching 75% and was not affected by coating with MTX-CS-NPs. Further, less than 5% of methotrexate was released after 80 h from uncoated NPs and the release was not enhanced by UV illumination of the particles. In contrast, the release from functionalized NPs was enhanced, reaching 40% after 80 h, as the particles were stroked with UV light and as the amount of TiO₂-NPs used in coating increased. Finally, coating the MTX-CS-NPs with TiO₂-NPs significantly enhanced their cytotoxicity on MCF-7 cells. The coated MTX-CS-NPs recorded low cell viabilities compared to the other formulations. In conclusion, the drug release of MTX-CS-NPs could be triggered and controlled remotely by coating with TiO₂-NPs, which maybe more effective in cancer treatment.

Formulation and Characterization of Tobramycin-Chitosan Nanoparticles Coated with Zinc Oxide Nanoparticles

Herein we describe the preparation, characterization and the antibacterial effect of Tobramycin-chitosan nanoparticles (TOB-CS NPs) coated with zinc oxide nanoparticles (ZnO NPs). Four formulations of TOB-CS NPs (A-D) were prepared to study the effect of experimental variables on the NPs behavior. Two formulations of ZnO NPs were prepared using the solvothermal and the precipitation methods (ZnO₁ and ZnO₂), and then characterized. TOB-CS NPs (Formula d) was coated with the ZnO₁. Moreover, the antibacterial activity of TOB-CS NPs, ZnO NPs and the coated nanoparticles against S. aureus and E. coli was examined. Changing the variables in preparing TOB-CS NPs resulting in variabilities in sizes (297.6–1116.3 nm), charges (+8.29–+39.00 mV), entrapment (51.95–90.60%). Further, TOB release was sustained over four days. ZnO NPs have sizes of 47.44 and 394.4 nm and charges of −62.3 and 89.4 mV when prepared by solvothermal and precipitation technique, respectively. Coated TOB-CS NPs had a size of 342 nm, a charge of +4.39 and released 100 µg/ mL of the drug after four days. The antimicrobial activity of TOB-CS NPs was lower than free TOB against S. aureus and E. coli. The coated NPs showed higher antimicrobial effect in comparison to formula D and ZnO₁. In conclusion, coating TOB-CS NPs with ZnO NPs exhibited a great antibacterial effect that may be sustained for days.

Sirolimus loaded chitosan functionalized poly (lactic-co-glycolic acid) (PLGA) nanoparticles for potential treatment of age-related macular degeneration

The usefulness of sirolimus (SIR) in the treatment of diseases that involve retinal degeneration like age-related macular degeneration (AMD) has been well documented. However, the problem still remains probably owing to the peculiar environment of the eye and/or unfavourable physiochemical profile of SIR. In the present work, we aimed to fabricate sirolimus loaded PLGA nanoparticles (SIR-PLGA-NP) and chitosan decorated PLGA nanoparticles (SIR-CH-PLGA-NP) to be administered via non-invasive subconjunctival route. Both the nanoparticles were characterized in terms of size, zeta potential, DSC, FTIR and XRD analysis. Quality by Design (QbD) approach was employed during the preparation of nanoparticles and the presence of chitosan coating was confirmed through thermogravimetric analysis and contact angle studies. Cationic polymer modification showed sustained in-vitro SIR release and enhanced ex-vivo scleral permeation and penetration. Further, SIR-CH-PLGA-NP revealed enhanced cellular uptake and thus, reduced lipopolysaccharide (LPS)-induced free-radicals generation by RAW 264.7 cells. The prepared nanoparticles were devoid of residual solvent and were found to be safe in HET-CAM analysis, RBCs damage analysis and histopathology studies. Moreover, high anti-angiogenic potential was observed in SIR-CH-PLGA-NP compared with SIR-PLGA-NP in chorioallantoic membrane (CAM) test. Overall, the current work opens up an avenue for further investigation of CH-PLGA-NP as SIR nanocarrier in the treatment of AMD.

A novel formulation of chitosan nanoparticles functionalized with titanium dioxide nanoparticles

Herein, chitosan nanoparticles (CS-NPs) were prepared and functionalized chemically with titanium dioxide nanoparticles (TiO₂-NPs) to allow on-demand degradation of CS-NPs, using ultraviolet (UV) irradiation as a trigger. This is expected to allow drug release depending on patients' needs or physiological circumstances. Eleven formulations were arranged and their particle size, charge, and polydispersity were determined. The effect of CS-NPs size and the amount of TiO₂-NPs, on the system collapse, was studied accordingly. Moreover, the collapse of these systems was examined using a fluorescence microscope after loading CS-NPs with Rhodamine. The formulations showed high monodispersity and had sizes ranged between 170 and 440 nm and charges ranged between +5 and +34 mV. Scanning electron microscope, Fourier-transform infrared spectroscopy, and X-ray diffraction proved the chemical deposition of TiO₂-NPs on CS-NPs. The dye test showed that there are two factors that oppose each other and affected the deposition of TiO₂-NPs on CS-NPs, the size of CS-NPs, and the amount of TiO₂-NPs used. In addition, the dye test showed that the deposition of TiO₂-NPs is a saturated process that relies on the amount of TiO₂-NPs used initially. Finally, the intensity of Rhodamine released from these systems after illumination with UV light was related to the amount of TiO₂-NPs deposited on CS-NPs. In conclusion, functionalization of CS-NPs with TiO₂-NPs can be controlled and used to rupture CS-NPs on demand by illumination with UV light.

Preparation and Characterization of Docetaxel-PLGA Nanoparticles Coated with Folic Acid-chitosan Conjugate for Cancer Treatment

The conjugation of chitosan (CS) and folic acid (FA) was prepared and used to coat PLGA nanoparticles (NPs) that are loaded with Docetaxel (DTX) to target cancer cells that have lower pH and overexpression of folate receptors in comparison to normal cells. Three formulations had been prepared to reach the highest loading capacity (LC%) and encapsulation efficiency (EE%) and to study the effect of the amount of FA-CS on the drug release. The sizes, charges, homogeneity, surface morphology, LC% and EE% of the NPs were determined. The NPs were characterized using FTIR and XRD. In vitro release profiles of DTX from PLGA NPs, at pH 5.5 and 7.4 were determined. Finally, in vitro cytotoxicity assay on three cancer cell lines (RPMI 2650, Calu-3, and A549) was studied. The sizes of the three formulations ranged between 250.3±1.7 and 356.3±17.7. All prepared formulations showed acceptable monodispersity with highly positive charges. The EE% was above 85% and the LC% ranged between 6-35%. The in vitro release of DTX show an inverse relation to the amounts of FA-CS used and the pH of the dissolution medium. Coated PLGA NPs showed a significant difference in RPMI 2650, Calu-3, and A549 cell viability in comparison to free DTX. The NPs components were safe and non-toxic to human cells. In conclusion, coating PLGA NPs with FA-CS may be used as a good carrier for chemotherapeutic agents that selectively target carcinogenic tissues.

Crucial Role of PLGA Nanoparticles in Mitigating the Amiodarone-Induced Pulmonary Toxicity

BACKGROUND

Amiodarone (AMD) is a widely used anti-arrhythmic drug, but its administration could be associated with varying degrees of pulmonary toxicity. In attempting to circumvent this issue, AMD-loaded polymeric nanoparticles (AMD-loaded NPs) had been designed.

MATERIALS AND METHODS

AMD was loaded in NPs by the nanoprecipitation method using two stabilizers: bovine serum albumin and Kolliphor® P 188. The physicochemical properties of the AMD-loaded NPs were determined. Among the prepared NPs, two ones were selected for further investigation of spectral and thermal analysis as well as morphological properties. Additionally, in vitro release patterns were studied and kinetically analyzed at different pH values. In vitro cytotoxicity of an optimized formula (NP4) was quantified using A549 and Hep-2 cell lines. In vivo assessment of the pulmonary toxicity on Sprague Dawley rats via histopathological and immunohistochemical evaluations was applied.

RESULTS

The developed NPs achieved a size not more than 190 nm with an encapsulation efficiency of more than 88%. Satisfactory values of loading capacity and yield were also attained. The spectral and thermal analysis demonstrated homogeneous entrapment of AMD inside the polymeric matrix of NPs. Morphology revealed uniform, core-shell structured, and sphere-shaped particles with a smooth surface. Furthermore, the AMD-loaded NPs exhibited a pH-dependent and diffusion-controlled release over a significant period without an initial burst effect. NP4 demonstrated a superior cytoprotective efficiency by diminishing cell death and significantly increasing the IC50 by more than threefold above the pure AMD. Also, NP4 ameliorated AMD-induced pulmonary damage in rats. Significant downregulation of inflammatory mediators and free radicle production were noticed in the NP4-treated rats.

CONCLUSION

The AMD-loaded NPs could ameliorate the pulmonary injury induced by the pure drug moieties. Cytoprotective, anti-fibrotic, anti-inflammatory, and antioxidant properties were presented by the optimized NPs (NP4). Future studies may be built on these findings for diminishing AMD-induced off-target toxicities.

Polymeric nano- and microparticulate drug delivery systems for treatment of biofilms

Now-a-days healthcare systems face great challenges with antibiotic resistance and low efficacy of antibiotics when combating pathogenic bacteria and bacterial biofilms. Administration of an antibiotic in its free form is often ineffective due to lack of selectivity to the infectious site and breakdown of the antibiotic before it exerts its effect. Therefore, polymeric delivery systems, where the antibiotic is encapsulated into a formulation, have shown great promise, facilitating a high local drug concentration at the site of infection, a controlled drug release and less drug degradation. All this leads to improved therapeutic effects and fewer systemic side effects together with a lower risk of developing antibiotic resistance. Here, we review and provide a comprehensive overview of polymer-based nano- and microparticles as carriers for antimicrobial agents and their effect on eradicating bacterial biofilms. We have a main focus on polymeric particulates containing poly(lactic-co-glycolic acid), chitosan and polycaprolactone, but also strategies involving combinations of these polymers are included. Different production techniques are reviewed and important parameters for biofilm treatment are discussed such as drug loading capacity, control of drug release, influence of particle size and mobility in biofilms. Additionally, we reflect on other promising future strategies for combating biofilms such as lipid-polymer hybrid particles, enzymatic biofilm degradation, targeted/triggered antibiotic delivery and future alternatives to the conventional particles.

Enhanced Eradication of Mucin-Embedded Bacterial Biofilm by Locally Delivered Antibiotics in Functionalized Microcontainers

Bacterial biofilm-related infections are difficult to eradicate and require repeated treatments with high doses of antibiotics. Thus, there is an urgent need for new treatment strategies that minimize the use of antibiotics while enhancing biofilm eradication. Functionalized reservoir-based microdevices, such as, microcontainers (MCs), offer, high drug loading capacity, mucus embedment, and tuneable drug release. Here, MCs are loaded with the antibiotic ciprofloxacin (CIP), and sealed with a lid consisting of chitosan (CHI) and a mucolytic agent, N-acetylcysteine (NAC). It is found that CHI and NAC work synergistically, showing improved mucoadhesive and mucolytic properties. To better mimic the in vivo habitat of Pseudomonas aeruginosa (P. aeruginosa), the biofilm is grown in a mucin-containing medium on a newly developed centrifugal microfluidic system. The CHI/NAC coated MCs improve eradication of biofilm (88.22 ± 2.89%) compared to CHI-coated MCs (72.68 ± 3.73%) or bolus injection (39.86 ± 13.28%). The findings suggest that MCs are significantly more efficient than a bolus treatment. Furthermore, CHI/NAC functionalized MCs kill most of the biomass already after 5 h (80.75 ± 3.50%), mainly due to a fast drug release. This is the first time that CHI/NAC has been combined as a coating to explore mucolytic properties on bacterial biofilms.

Nano-Strategies for Improving the Bioavailability of Inhaled Pharmaceutical Formulations

Pulmonary pharmaceutical formulations are targeted for the treatment of respiratory diseases. However, their application is limited due to the physiological characteristics of the lungs, such as branching structure, mucociliary and macrophages, as well as certain properties of the drugs like particle size and solubility. Nano-formulations can ameliorate particle sizes and improve drug solubility to enhance bioavailability in the lungs. The nano-formulations for lungs reviewed in this article can be classified into nanocarriers, no-carrier-added nanosuspensions and polymer-drug conjugates. Compared with conventional inhalation preparations, these novel pulmonary pharmaceutical formulations have their own advantages, such as increasing drug solubility for better absorption and less inflammatory reaction caused by the aggregation of insoluble drugs; prolonging pulmonary retention time and reducing drug clearance; improving the patient compliance by avoiding multiple repeated administrations. This review will provide the reader with some background information for pulmonary drug delivery and give an overview of the existing literature about nano-formulations for pulmonary application to explore nano-strategies for improving the bioavailability of pulmonary pharmaceutical formulations.

Nanoparticle-mediated pulmonary drug delivery: state of the art towards efficient treatment of recalcitrant respiratory tract bacterial infections

Recalcitrant respiratory tract infections caused by bacteria have emerged as one of the greatest health challenges worldwide. Aerosolized antimicrobial therapy is becoming increasingly attractive to combat such infections, as it allows targeted delivery of high drug concentrations to the infected organ while limiting systemic exposure. However, successful aerosolized antimicrobial therapy is still challenged by the diverse biological barriers in infected lungs. Nanoparticle-mediated pulmonary drug delivery is gaining increasing attention as a means to overcome the biological barriers and accomplish site-specific drug delivery by controlling release of the loaded drug(s) at the target site. With the aim to summarize emerging efforts in combating respiratory tract infections by using nanoparticle-mediated pulmonary delivery strategies, this review provides a brief introduction to the bacterial infection-related pulmonary diseases and the biological barriers for effective treatment of recalcitrant respiratory tract infections. This is followed by a summary of recent advances in design of inhalable nanoparticle-based drug delivery systems that overcome the biological barriers and increase drug bioavailability. Finally, challenges for the translation from exploratory laboratory research to clinical application are also discussed and potential solutions proposed.

Progress in the Application of Nano- and Micro-based Drug Delivery Systems in Pulmonary Drug Delivery

Nanotechnology is associated with the development of particles in the nano-size range that can be used in a wide range of applications in the medical field. It has gained more importance in the pharmaceutical research field particularly in drug delivery, as it results in enhanced therapeutic drug performance, improved drug solubility, targeted drug delivery to the specific sites, minimized side effects, and prolonged drug retention time in the targeted site. To date, the application of nanotechnology continues to offer several benefits in the treatment of various chronic diseases and results in remarkable improvements in treatment outcomes. The use of nano-based delivery systems such as liposomes, micelles, and nanoparticles in pulmonary drug delivery have shown to be a promising strategy in achieving drug deposition and maintained controlled drug release in the lungs. They have been widely used to minimize the risks of drug toxicity in vivo. In this review, recent advances in the application of nano- and micro-based delivery systems in pulmonary drug delivery for the treatment of various pulmonary diseases, such as lung cancer, asthma, and chronic obstructive pulmonary disease, are highlighted. Limitations in the application of these drug delivery systems and some key strategies in improving their formulation properties to overcome challenges encountered in drug delivery are also discussed.

Potential of mucoadhesive nanocapsules in drug release and toxicology in zebrafish

Mucoadhesive polymeric nanocapsules have attracted interest of researchers from different fields from natural sciences because of their ability to interact with the mucosa and increase drug permeation. Anesthesia by immersion causes absorption through the skin and gills of fish, so it is important to evaluate the exposure of these organs to drug nanosystems. Benzocaine (BENZ) is one of the most popular anesthetic agents used in fish anesthesia, but it has drawbacks because of its low bioavailability, resulting in weak absorption after immersion. Here we describe method developed for preparing and characterizing chitosan-coated PLGA mucoadhesive nanoparticles containing BENZ (NPMAs) for zebrafish immersion anesthesia. We determined the lowest effective concentration, characterized the interaction of the mucoadhesive system with fish, measured the anesthetic efficacy, and evaluated possible toxic effects in embryos and adults exposed to the nanoformulations. This study opens perspectives for using nanoformulations prepared with BENZ in aquaculture, allowing reduction of dosage as well as promoting more effective anesthesia and improved interaction with the mucoadhesive system of fish.

Comparative Nanofabrication of PLGA-Chitosan-PEG Systems Employing Microfluidics and Emulsification Solvent Evaporation Techniques

Poor circulation stability and inadequate cell membrane penetration are significant impediments in the implementation of nanocarriers as delivery systems for therapeutic agents with low bioavailability. This research discusses the fabrication of a biocompatible poly(lactide-co-glycolide) (PLGA) based nanocarrier with cationic and hydrophilic surface properties provided by natural polymer chitosan and coating polymer polyethylene glycol (PEG) for the entrapment of the hydrophobic drug disulfiram. The traditional emulsification solvent evaporation method was compared to a microfluidics-based method of fabrication, with the optimisation of the parameters for each method, and the PEGylation densities on the experimental nanoparticle formulations were varied. The size and surface properties of the intermediates and products were characterised and compared by dynamic light scattering, scanning electron microscopy and X-ray diffraction, while the thermal properties were investigated using thermogravimetric analysis and differential scanning calorimetry. Results showed optimal particle properties with an intermediate PEG density and a positive surface charge for greater biocompatibility, with nanoparticle surface characteristics shielding physical interaction of the entrapped drug with the exterior. The formulations prepared using the microfluidic method displayed superior surface charge, entrapment and drug release properties. The final system shows potential as a component of a biocompatible nanocarrier for poorly soluble drugs.

Comparative study of mucoadhesive and mucus-penetrative nanoparticles based on phospholipid complex to overcome the mucus barrier for inhaled delivery of baicalein

Efficient mucosal delivery remains a major challenge for the reason of the respiratory tract mucus act as a formidable barrier to nanocarriers by trapping and clearing foreign particulates. The surface property of nanoparticles determines their retention and penetration ability within the respiratory tract mucus. However, the interaction between nanoparticles and mucus, and how these interactions impact distribution has not been extensively investigated. In this study, polymeric nanoparticles loaded with a baicalein–phospholipid complex were modified with two kinds of polymers, mucoadhesive and mucus-penetrative polymer. Systematic investigations on the physicochemical property, mucus penetration, transepithelial transport, and tissue distribution were performed to evaluate the interaction of nanoparticles with the respiratory tract. Both nanoparticles had a similar particle size and good biocompatibility, exhibited a sustained-release profile, but showed a considerable difference in zeta potential. Interestingly, mucus-penetrative nanoparticles exhibited a higher diffusion rate in mucus, deeper penetration across the mucus layer, enhanced in vitro cellular uptake, increased drug distribution in airways, and superior local distribution and bioavailability as compared to mucoadhesive nanoparticles. These results indicate the potential of mucus-penetrative nanoparticles in design of a rational delivery system to improve the efficiency of inhaled therapy by promoting mucus penetration and increasing local distribution and bioavailability.

Pharmacokinetic profile of chitosan modified poly lactic co-glycolic acid biodegradable nanoparticles following oral delivery of gentamicin in rabbits

Gentamicin (GM) is a well know antibiotic and drug of choice for various infections and is available in the form of parenteral and topical formulations. Gentamicin has no oral dosage form due to its enzymatic degradation and poor bioavailability. This study was designed to optimize controlled release oral dosage form of GM using poly lactic co-glycolic acid (PLGA) nanoparticles (NPs) which were surface modified with chitosan. Nanoparticles were characterized for size, potential, scanning electron microscopy and fourier transform infrared spectroscopy. Drug concentration in plasma samples was determined by microbiological assay against Bacillus subtilis (ATCC 9372). In vitro release pattern was studied and the best formulation was administered to healthy rabbits for pharmacokinetic studies. Various pharmacokinetic parameters determined for oral formulation were area under the curve (AUC) 43.2 ± 2.16 h.mg/L, volume of distribution (Vd) 1.54 ± 0.25 L, half-life phase-1 (t_1/2α) 0.59 ± 0.12 h, mean residence time (MRT) 11.22 ± 0.42 h, time to reach maximum concentration (Tmax) 2.56 ± 0.09 h and maximum concentration (Cmax) was 3.49 ± 0.10 mg/L. It is concluded that chitosan modified GM loaded PLGA NPs has potential for oral absorption and can be used for achieving therapeutic benefits.

Nanosystems for the Encapsulation of Natural Products: The Case of Chitosan Biopolymer as a Matrix

Chitosan is a cationic natural polysaccharide, which has emerged as an increasingly interesting biomaterialover the past few years. It constitutes a novel perspective in drug delivery systems and nanocarriers' formulations due to its beneficial properties, including biocompatibility, biodegradability and low toxicity. The potentiality of chemical or enzymatic modifications of the biopolymer, as well as its complementary use with other polymers, further attract the scientific community, offering improved and combined properties in the final materials. As a result, chitosan has been extensively used as a matrix for the encapsulation of several valuable compounds. In this review article, the advantageous character of chitosan as a matrix for nanosystemsis presented, focusing on the encapsulation of natural products. A five-year literature review is attempted covering the use of chitosan and modified chitosan as matrices and coatings for the encapsulation of natural extracts, essential oils or pure naturally occurring bioactive compounds are discussed.

Preparation of PLGA-chitosan based nanocarriers for enhancing antibacterial effect of ciprofloxacin in root canal infection

The aim of this study is to prepare and evaluate the antibacterial and antibiofilm activity of ciprofloxacin (CIP) loaded PLGA nanoparticles (F2) and CIP-PLGA nanoparticles coated with chitosan (F3) versus ciprofloxacin solution (Fl) as a control on Enterococcus faecalis. F2 was prepared using double emulsion evaporation technique then coated with chitosan (F3). The prepared F2 and F3 were evaluated for size, surface charge, encapsulation efficiency, morphology and in vitro release. F1, F2, F3, and Chitosan (CS) were assessed in vitro using agar diffusion technique and biofilm inhibition assay. Finally, biofilm inhibition on teeth using Colony Forming Unit (CFU) was implemented with different concentrations of the three formulae. The results revealed that F2 is 202.9 nm with a negative charge −0.0254 mv, while F3 is 339.6 nm with a positive charge +28.5 mv. The encapsulation efficiency of F2, and F3 was 64% and 78% respectively. The amount released was 92.62% and 78.3% for F2 and F3, respectively, after 72 h, while F1 showed 100% released in the first hour. CS, F1, F2, and F3, showed antibacterial effect with inhibition zone of 12 mm, 22 mm, 20 mm, and 32 mm respectively. Biofilm inhibition of F1, F2, and F3 were 60%, 74%, and 91.8%, respectively. F3 colony count was less than F2, and F1 in all concentrations. It can be concluded that F3 had proven to exhibit potential antibacterial and antibiofilm activity in a controlled release pattern consequently, they can be used as an intra-canal medication.

Preparation and Characterization of Chitosan Coated PLGA Nanoparticles of Resveratrol: Improved Stability, Antioxidant and Apoptotic Activities in H1299 Lung Cancer Cells

Resveratrol (RES) is a polyphenolic compound which has shown beneficial pharmacological effects such as anti-inflammatory, antioxidant, and anti-cancer effects. However, poor aqueous solubility, bioavailability, and low stability are the major limitations to the clinical application of RES. Therefore, in the present study, chitosan (CS) coated PLGA nanoparticles of RES (CS-RES-PLGA NPs) was developed, characterized and its anticancer activity was evaluated in the H1299 lung carcinoma cell line. The effects of the increase in CS coating and cryoprotectant concentration on particle size, polydispersity index (PDI) and zeta potential (ZP) were determined. The particle size, PDI, ZP and entrapment efficiency of the optimized CS-RES-PLGA NPs were found to be 341.56 ± 7.90 nm, 0.117 ± 0.01, 26.88 ± 2.69 mV and 75.13% ± 1.02% respectively. The average particle size and ZP showed a steady increase with an increase in CS concentration. The increase in positive zeta potential is evident for higher CS concentrations. The effect of trehalose as cryoprotectant on average particle size was decreased significantly (p < 0.05) when it was increased from 1%−5% w/v. TEM and SEM showed uniform particle distribution with a smooth surface and spherical shape. The CS coating provides modulation of in vitro drug release and showed a sustained release pattern. The stability of RES loaded PLGA NPs was improved by CS coating. CS-coated NPs showed greater cytotoxicity and apoptotic activities compared to free RES. The CS coated NPs had a higher antioxidant effect than the free RES. Therefore, CS coated PLGA NPs could be a potential nanocarrier of RES to improve drug solubility, entrapment, sustain release, stability and therapeutic application.

Thymoquinone-PLGA-PVA Nanoparticles Ameliorate Bleomycin-Induced Pulmonary Fibrosis in Rats via Regulation of Inflammatory Cytokines and iNOS Signaling

Pulmonary fibrosis is considered one of the most chronic interstitial illnesses which are not easily treated. thymoquinone's (TQ) benefits are still partly problematic due to poor water solubility; therefore, it was loaded onto PLGA-PVA carriers. This study aimed to evaluate the potential effect of TQ-PLGA-PVA nanoparticles (TQ-PLGA-PVA-NPs) on pulmonary fibrosis induced by bleomycin in albino rats. Forty male rats were randomized into four groups. The first group served as the control group; the second and the third groups received bleomycin intratracheally, whereas the third group received TQ-PLGA-PVA-NPs after 4 weeks from bleomycin administration. The fourth group was administrated TQ-PLGA-PVA-NPs alone. The designed nanoparticles appeared around 20 nm size (10-30 nm), had a spherical shape, and had 80% encapsulation efficiency. The histological examination of rats simultaneously treated with TQ-PLGA-PVA-NPs and bleomycin revealed reduction in the thickness of the alveolar septa and improvement of the other lung structures, with the presence of lymphocytes admixed with exfoliated epithelium in a few lumina remaining. Ultrastructural findings revealed marked collagenolysis and the release of nanoparticles from ruptured pneumocytes within the alveolar septa after 14 days from TQ-PLGA-PVA-NPs administration. Very active pneumocyte types II were seen in the TQ-PLGA-PVANP group. Additionally, immunohistochemical expression of inducible nitric oxide (iNOS) and estimation of inflammatory cytokines in lung tissues including interleukin 10 (IL 10) and transforming growth factor-beta (TGF-β1) confirmed the antioxidant and anti-inflammatory effects of TQ-PLGA-PVANPs. The study concluded that TQ-PLGA-PVA-NPs could attenuate the bleomycin-induced pulmonary fibrosis, through the inhibition of lung inflammation and the suppression of bleomycin- induced oxidative stress.

Synthesis and characterization of photocatalytic polyurethane and poly(methyl methacrylate) microcapsules for the controlled release of methotrexate

The aim of this work is to prepare ultraviolet (UV) triggered controlled release of compounds from microcapsule systems (MCs). Polyurethane (PU) and poly(methyl methacrylate) (PMMA) microcapsules were studied with/without chemical functionalization using photocatalytic TiO₂ nanoparticles (NPs) on their surface. Once TiO₂ nanoparticles are illuminated with UV light (λ = 370 nm), they initiate the rupture of the polymeric bonds of the microcapsule and subsequently initiate the encapsulated compound release, methotrexate (MTX) or rhodamine (Rh), in the present work. The size, polydispersity, charge, and yield of all MCs were measured, being the methotrexate drug release for all systems determined and compared with and without functionalization with TiO₂ NPs, under dark, visible light and UV illumination in vitro. Finally, the Rh release was characterized using fluorescence microscopy. The TiO₂ NPs size is around 10 nm, as determined by X-ray diffraction experiments. The PU MCs average size is around 60 µm, its electric charge +3.11 mV and yield around 85%. As for the PMMA MCs, the average size is around 280 µm, its electric charge -7.2 mV and yield around 25% and 30% for both MTX and Rh, respectively. In general, adding TiO₂ NPs or the encapsulated products to the MCs does not affect the size but functionalization with TiO₂ NPs lowers the electric charge. Microcapsules functionalized with TiO₂ nanoparticles and irradiated with UV light presented the highest release of MTX and Rh. All other samples showed lower drug release levels when studied under the same conditions.