Chitosan Oleate Coated Poly Lactic-Glycolic Acid (PLGA) Nanoparticles versus Chitosan Oleate Self-Assembled Polymeric Micelles, Loaded with Resveratrol

Drug Polymeric Carrier of Aceclofenac Based on Amphiphilic Chitosan Micelles

Amphiphilic micelles based on chitosan (CS) were applied as drug carriers of aceclofenac (ACF) as a potential method to induce its bioavailability and therapeutic efficiency. N-octyl-N,O-succinyl CS (OSCS), an amphiphilic CS derivative, was successfully synthesized and loaded physically by ACF at different pH values and using different dosages of ACF, forming ACF-loaded polymeric micelles (PMs). The obtained PMs and ACF-loaded PMs were characterized by different analytical techniques, including AFM, TEM, DLS, UV-vis spectrophotometry, 1H NMR spectroscopy, and FT-IR spectroscopy. The pH 5 sample with a 30% ACF/polymer ratio showed the highest ACF loading capacity (LC) and entrapment efficiency (EE). In vitro release behaviors of pure ACF and ACF-loaded PMs at each release point indicated that the release profile of pH-responsive PMs loaded with ACF demonstrated quicker release rates (94% after 480 min) compared to the release behavior noticed for free ACF (59.56% after 480 min). Furthermore, the release rates exhibit a notable rise when the pH is increased from 1.2 to 4.7. In the carrageenan-induced inflammation model of paw edema in rats, it has been demonstrated that the injection of ACF-loaded PMs (at a dose of 10 mg/kg) resulted in a strengthened inflammatory activity compared to the injection of free ACF at equivalent dosages as well as at time intervals. However, the use of ACF-loaded PMs for a duration of 6 h displayed a notable reduction of paw edema, with an inhibition percentage of 85.09%, in contrast to the 74.9% inhibition percentage observed for the free ACF medication.

Development of Berberine-Loaded Nanoparticles for Astrocytoma Cells Administration and Photodynamic Therapy Stimulation

Berberine (BBR) is known for its antitumor activity and photosensitizer properties in anti-cancer photodynamic therapy (PDT), and it has previously been favorably assayed against glioblastoma multiforme (GBM)-derived cells. In this work, two BBR hydrophobic salts, dodecyl sulfate (S) and laurate (L), have been encapsulated in PLGA-based nanoparticles (NPs), chitosan-coated by the addition of chitosan oleate in the preparation. NPs were also further functionalized with folic acid. All the BBR-loaded NPs were efficiently internalized into T98G GBM established cells, and internalization increased in the presence of folic acid. However, the highest mitochondrial co-localization percentages were obtained with BBR-S NPs without folic acid content. In the T98G cells, BBR-S NPs appeared to be the most efficient in inducing cytotoxicity events and were therefore selected to assess the effect of photodynamic stimulation (PDT). As a result, PDT potentiated the viability reduction for the BBR-S NPs at all the studied concentrations, and a roughly 50% reduction of viability was obtained. No significant cytotoxic effect on normal rat primary astrocytes was observed. In GBM cells, a significant increase in early and late apoptotic events was scored by BBR NPs, with a further increase following the PDT scheme. Furthermore, a significantly increased depolarization of mitochondria was highlighted following BBR-S NPs’ internalization and mostly after PDT stimulation, compared to untreated and PDT-only treated cells. In conclusion, these results highlighted the efficacy of the BBR-NPs-based strategy coupled with photoactivation approaches to induce favorable cytotoxic effects in GBM cells.

DEC-205 receptor targeted poly(lactic-co-glycolic acid) nanoparticles containing Eucommia ulmoides polysaccharide enhances the immune response of foot-and-mouth disease vaccine in mice

Nanoparticles targeting the DEC-205 receptor were found to induce antigen-specific protective immune response. When the delivery system carries both antigens and immunomodulators, it can maximize the expected therapeutic effect of the drug and induce effective humoral and cellular immune responses to antigens.In this study, we encapsulated the Eucommia ulmoides Oliv. polysaccharides (EUPS) into PLGA nanoparticles (NPs) and conjugated it with anti-CD205 monoclonal Ab (MAb) to produce a DEC-205 receptor targeted PLGA nanoparticles (anti-DEC-205-EUPS-PLGA NPs). The physicochemical characteristics and adjuvant activity of the above NPs were evaluated in vitro and in vivo. In the in vitro setting, 200 μg·mL^-1 anti-DEC-205-EUPS-PLGA could improve the proliferation of DCs and promote their antigen up-take activity. In the in vivo setting, anti-DEC-205-EUPS-PLGA NPs remarkably controlled the release of drug and antigen to induce sustained immune responses and up-regulated the levels of FMDV-specific IgG antibodies, promoted the cytotoxic activity of CTLs and NK cells, and improved the proliferation of splenocytes. Moreover, the anti-DEC-205-EUPS-PLGA NPs facilitated the maturation of DCs. The above data indicated that anti-DEC-205-EUPS-PLGA NPs employed as an targeted adjuvant induced the humoral and cellular immune activity by promoting the maturation of DCs. These findings may provide a new insight onto the development of vaccine adjuvants.

Neuro-nanotechnology: diagnostic and therapeutic nano-based strategies in applied neuroscience

Artificial, de-novo manufactured materials (with controlled nano-sized characteristics) have been progressively used by neuroscientists during the last several decades. The introduction of novel implantable bioelectronics interfaces that are better suited to their biological targets is one example of an innovation that has emerged as a result of advanced nanostructures and implantable bioelectronics interfaces, which has increased the potential of prostheses and neural interfaces. The unique physical-chemical properties of nanoparticles have also facilitated the development of novel imaging instruments for advanced laboratory systems, as well as intelligently manufactured scaffolds and microelectrodes and other technologies designed to increase our understanding of neural tissue processes. The incorporation of nanotechnology into physiology and cell biology enables the tailoring of molecular interactions. This involves unique interactions with neurons and glial cells in neuroscience. Technology solutions intended to effectively interact with neuronal cells, improved molecular-based diagnostic techniques, biomaterials and hybridized compounds utilized for neural regeneration, neuroprotection, and targeted delivery of medicines as well as small chemicals across the blood-brain barrier are all purposes of the present article.

Exploring the role of nanomedicines for the therapeutic approach of central nervous system dysfunction: At a glance

In recent decades, research scientists, molecular biologists, and pharmacologists have placed a strong emphasis on cutting-edge nanostructured materials technologies to increase medicine delivery to the central nervous system (CNS). The application of nanoscience for the treatment of neurodegenerative diseases (NDs) such as Alzheimer’s disease (AD), Parkinson’s disease (PD), multiple sclerosis (MS), Huntington’s disease (HD), brain cancer, and hemorrhage has the potential to transform care. Multiple studies have indicated that nanomaterials can be used to successfully treat CNS disorders in the case of neurodegeneration. Nanomedicine development for the cure of degenerative and inflammatory diseases of the nervous system is critical. Nanoparticles may act as a drug transporter that can precisely target sick brain sub-regions, boosting therapy success. It is important to develop strategies that can penetrate the blood–brain barrier (BBB) and improve the effectiveness of medications. One of the probable tactics is the use of different nanoscale materials. These nano-based pharmaceuticals offer low toxicity, tailored delivery, high stability, and drug loading capacity. They may also increase therapeutic effectiveness. A few examples of the many different kinds and forms of nanomaterials that have been widely employed to treat neurological diseases include quantum dots, dendrimers, metallic nanoparticles, polymeric nanoparticles, carbon nanotubes, liposomes, and micelles. These unique qualities, including sensitivity, selectivity, and ability to traverse the BBB when employed in nano-sized particles, make these nanoparticles useful for imaging studies and treatment of NDs. Multifunctional nanoparticles carrying pharmacological medications serve two purposes: they improve medication distribution while also enabling cell dynamics imaging and pharmacokinetic study. However, because of the potential for wide-ranging clinical implications, safety concerns persist, limiting any potential for translation. The evidence for using nanotechnology to create drug delivery systems that could pass across the BBB and deliver therapeutic chemicals to CNS was examined in this study.

Association of Indocyanine Green with Chitosan Oleate Coated PLGA Nanoparticles for Photodynamic Therapy

Indocyanine green (ICG) is a safe dye widely used in the biomedical field. Its photodynamic effect (PDT), originating from laser irradiation at 803 nm, opens interesting perspectives in theranostic applications. To overcome its low water stability, ICG can be shielded with nanoparticles (NPs). In this work, previously developed NPs based on poly lactic-co-glycolic acid (PLGA) coated with chitosan oleate (CS-OA) and loaded with resveratrol as a hydrophobic model drug have been proposed as an ICG carrier. These systems have been selected for their observed immunostimulatory properties. The possible loading of the dye by adsorption onto NP surface by electrostatic interaction was studied here in comparison with the encapsulation into the PLGA core. The ICG-chitosan (CS) interaction has been characterized by spectrophotometry, spectroscopy and in-cell in vitro assays. Fluorescence quenching was observed due to the ionic interaction between ICG and CS and was studied considering the dye:polymer stoichiometry and the effect of the NP dilution in cell culture medium (DMEM). The NP systems have been compared in vitro, assessing their behaviour in Caco-2 cell lines. A reduction in cell viability was observed after irradiation of ICG associated with NPs, evident also for the samples loaded by adsorption. These findings open the opportunity to exploit the association of PDT’s effect on ICG with the properties of CS-OA coated NPs, whose immunostimulatory effect can be associated with PDT mechanism in cancer therapy.

Chitosan Oleate Coated PLGA Nanoparticles as siRNA Drug Delivery System

Oligonucleotide therapeutics such as miRNAs and siRNAs represent a class of molecules developed to modulate gene expression by interfering with ribonucleic acids (RNAs) and protein synthesis. These molecules are characterized by strong instability and easy degradation due to nuclease enzymes. To avoid these drawbacks and ensure efficient delivery to target cells, viral and non-viral vectors are the two main approaches currently employed. Viral vectors are one of the major vehicles in gene therapy; however, the potent immunogenicity and the insertional mutagenesis is a potential issue for the patient. Non-viral vectors, such as polymeric nanocarriers, provide a safer and more efficient delivery of RNA-interfering molecules. The aim of this work is to employ PLGA core nanoparticles shell-coated with chitosan oleate as siRNA carriers. An siRNA targeted on HIV-1, directed against the viral Tat/Rev transcripts was employed as a model. The ionic interaction between the oligonucleotide's moieties, negatively charged, and the positive surface charges of the chitosan shell was exploited to associate siRNA and nanoparticles. Non-covalent bonds can protect siRNA from nuclease degradation and guarantee a good cell internalization and a fast release of the siRNA into the cytosolic portion, allowing its easy activation.

Chitosan-Based Anti-Oxidation Delivery Nano-Platform: Applications in the Encapsulation of DHA-Enriched Fish Oil

Refined cobia liver oil is a nutritional supplement (CBLO) that is rich in polyunsaturated fatty acids (PUFAs), such as DHA and EPA; however, PUFAs are prone to oxidation. In this study, the fabrication of chitosan-TPP-encapsulated CBLO nanoparticles (CS@CBLO NPs) was achieved by a two-step method, including emulsification and the ionic gelation of chitosan with sodium tripolyphosphate (TPP). The obtained nanoparticles were inspected by dynamic light scattering (DLS) and showed a positively charged surface with a z-average diameter of between 174 and 456 nm. Thermogravimetric analysis (TGA) results showed the three-stage weight loss trends contributing to the water evaporation, chitosan decomposition, and CBLO decomposition. The loading capacity (LC) and encapsulation efficiency (EE) of the CBLO loading in CS@CBLO NPs were 17.77-33.43% and 25.93-50.27%, respectively. The successful encapsulation of CBLO in CS@CBLO NPs was also confirmed by the Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques. The oxidative stability of CBLO and CS@CBLO NPs was monitored by FTIR. As compared to CBLO, CS@CBLO NPs showed less oxidation with a lower generation of hydroperoxides and secondary oxidation products after four weeks of storage. CS@CBLO NPs are composed of two ingredients that are beneficial for health, chitosan and fish oil in a nano powdered fish oil form, with an excellent oxidative stability that will enhance its usage in the functional food and pharmaceutical industries.

Polymeric micelles in cancer therapy: State of the art

In recent years, polymeric micelles have been extensively utilized in pre-clinical studies for delivering poorly soluble chemotherapeutic agents in cancer. Polymeric micelles are formed via self-assembly of amphiphilic polymers in facile manners. The wide availability of hydrophobic and, to some extent, hydrophilic polymeric blocks allow researchers to explore various polymeric combinations for optimum loading, stability, systemic circulation, and delivery to the target cancer tissues. Moreover, polymeric micelles could easily be tailor-made by increasing and decreasing the number of monomers in each polymeric chain. Some of the widely accepted hydrophobic polymers are poly(lactide) (PLA), poly(caprolactone) (PCL), poly(lactide-co-glycolide) (PLGA), polyesters, poly(amino acids), lipids. The hydrophilic polymers used to wrap the hydrophobic core are poly(ethylene glycol), poly(oxazolines), chitosan, dextran, and hyaluronic acids. Drugs could be conjugated to polymers at the distal ends to prepare pharmacologically active polymeric systems that impart enhanced solubility and stability of the conjugates and provide an opportunity for combination drug delivery. Their nano-size enables them to accumulate to the tumor microenvironment via the Enhanced Permeability and Retention (EPR) effect. Moreover, the stimuli-sensitive breakdown provides the micelles an effective means to deliver the therapeutic cargo effectively. The tumor micro-environmental stimuli are pH, hypoxia, and upregulated enzymes. Externally applied stimuli to destroy micellar disassembly to release the payload include light, ultrasound, and temperature. This article delineates the current trend in developing polymeric micelles combining various block polymeric scaffolds. The development of stimuli-sensitive micelles to achieve enhanced therapeutic activity are also discussed.

Nanoformulations to Enhance the Bioavailability and Physiological Functions of Polyphenols

Polyphenols are micronutrients that are widely present in human daily diets. Numerous studies have demonstrated their potential as antioxidants and anti-inflammatory agents, and for cancer prevention, heart protection and the treatment of neurodegenerative diseases. However, due to their vulnerability to environmental conditions and low bioavailability, their application in the food and medical fields is greatly limited. Nanoformulations, as excellent drug delivery systems, can overcome these limitations and maximize the pharmacological effects of polyphenols. In this review, we summarize the biological activities of polyphenols, together with systems for their delivery, including phospholipid complexes, lipid-based nanoparticles, protein-based nanoparticles, niosomes, polymers, micelles, emulsions and metal nanoparticles. The application of polyphenol nanoparticles in food and medicine is also discussed. Although loading into nanoparticles solves the main limitation to application of polyphenolic compounds, there are some concerns about their toxicological safety after entry into the human body. It is therefore necessary to conduct toxicity studies and residue analysis on the carrier.

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.

Assessment of Residual Solvent and Drug in PLGA Microspheres by Derivative Thermogravimetry

Thermogravimetry does not give specific information on residual organic solvents in polymeric matrices unless it is hyphenated with the so-called evolved gas analysis. The purpose of this study was to apply, for the first time, derivative thermogravimetry (DTG) to characterize a residual solvent and a drug in poly-d,l-lactide-co-glycolide (PLGA) microspheres. Ethyl formate, an ICH class 3 solvent, was used to encapsulate progesterone into microspheres. DTG provided a distinct peak, displaying the onset and end temperatures at which ethyl formate started to evolve from to where it completely escaped out of the microspheres. DTG also gave the area and height of the solvent peak, as well as the temperature of the highest mass change rate of the microspheres. These derivative parameters allowed for the measurement of the amount of residual ethyl formate in the microspheres. Interestingly, progesterone affected not only the residual solvent amount but also these derivative parameters. Another intriguing finding was that there was a linear relationship between progesterone content and the peak height of ethyl formate. The residual solvent data calculated by DTG were quite comparable to those measured by gas chromatography. In summary, DTG could be an efficient and practical quality control tool to evaluate residual solvents and drugs in various polymeric matrices.

Nanotechnology: A Promising Approach for Delivery of Neuroprotective Drugs

Central nervous system (CNS) disorders especially neurodegenerative disorders are the major challenge for public health and demand the great attention of researchers to protect people against them. In past few decades, different treatment strategies have been adopted, but their therapeutic efficacy are not enough and have only shown partial mitigation of symptoms. Blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BSCFB) guard the CNS from harmful substances and pose as the major challenges in delivering drugs into CNS for treatment of CNS complications such as Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), stroke, epilepsy, brain tumors, multiple sclerosis (MS), and encephalitis, etc. Nanotechnology has come out as an exciting and promising new platform of treating neurological disorders and has shown great potential to overcome problems related to the conventional treatment approaches. Molecules can be nanoengineered to carry out multiple specific functions such as to cross the BBB, target specific cell or signaling pathway, respond to endogenous stimuli, and act as a vehicle for gene delivery, support nerve regeneration and cell survival. In present review, the role of nanocarrier systems such as liposomes, micelles, solid lipid nanoparticles (SLNPs), dendrimers, and nanoemulsions for delivery of various neurotherapeutic agents has been discussed, besides this, their mechanism of action, and nanoformulation of different neuroprotective agents like curcumin, edaravone, nerve growth factors in CNS disorders like Alzheimer’s, Parkinsonism, epilepsy, stroke, and brain tumors has been reviewed.

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.