Nanoparticle-Mediated Dual Targeting: An Approach for Enhanced Baicalin Delivery to the Liver

Enhancing the therapeutic potential of isoliensinine for hypertension through PEG-PLGA nanoparticle delivery: A comprehensive in vivo and in vitro study

BACKGROUND

Hypertension, a highly prevalent chronic disease, is known to inflict severe damage upon blood vessels. In our previous study, isoliensinine, a kind of bibenzyl isoquinoline alkaloid which isolated from a TCM named Lotus Plumule (Nelumbo nucifera Gaertn), exhibits antihypertensive and vascular smooth muscle proliferation-inhibiting effects, but its application is limited due to poor water solubility and low bioavailability. In this study, we proposed to prepare isoliensinine loaded by PEG-PLGA polymer nanoparticles to increase its efficacy METHOD: We synthesized and thoroughly characterized PEG-PLGA nanoparticles loaded with isoliensinine using a nanoprecipitation method, denoted as, PEG-PLGA@Isoliensinine. Additionally, we conducted comprehensive investigations into the stability of PEG-PLGA@Isoliensinine, in vitro drug release profiles, and in vivo pharmacokinetics. Furthermore, we assessed the antihypertensive efficacy of this nano-system through in vitro experiments on A7R5 cells and in vivo studies using AngII-induced mice.

RESULT

The findings reveal that PEG-PLGA@Isoliensinine significantly improves isoliensinine absorption by A7R5 cells and enhances targeted in vivo distribution. This translates to a more effective reduction of AngII-induced hypertension and vascular smooth muscle proliferation.

CONCLUSION

In this study, we successfully prepared PEG-PLGA@Isoliensinine by nano-precipitation, and we confirmed that PEG-PLGA@Isoliensinine surpasses free isoliensinine in its effectiveness for the treatment of hypertension, as demonstrated through both in vivo and in vitro experiments.

SIGNIFICANCE

This study lays the foundation for isoliensinine's clinical use in hypertension treatment and vascular lesion protection, offering new insights for enhancing the bioavailability of traditional Chinese medicine components. Importantly, no toxicity was observed, affirming the successful implementation of this innovative drug delivery system in vivo and offers a promising strategy for enhancing the effectiveness of Isoliensinine and propose an innovative avenue for developing novel formulations of traditional Chinese medicine monomers.

Preparation and characterisation of baicalin magnesium and its protective effect in ulcerative colitis via gut microbiota-bile acid axis modulation

BACKGROUND

Scutellaria baicalensis Georgi is a well-known herb in traditional Chinese medicine that is frequently prescribed for various gastrointestinal conditions, including ulcerative colitis (UC). Its primary active constituent, baicalin, has poorly water solubility that reduces its efficacy.

PURPOSE

To enhance the aqueous solubility of baicalin by optimising its extraction process. We compared the modulatory effects of isolated water-soluble baicalin and water-insoluble baicalin on UC, and delved deeper into the potential mechanisms of water-soluble baicalin.

METHODS

We successfully extracted a more hydrophilic baicalin directly from an aqueous S. baicalensis Georgi extract through the process of recrystallisation following alcoholic precipitation of the aqueous extract obtained from S. baicalensis Georgi, eliminating the need for acid additives. This specific form of baicalin was conclusively identified by UV, IR, atomic absorption spectroscopy, elemental analysis, 1H NMR, 13C NMR, and ESI-HRMS. We subsequently compared the regulatory effects of baicalin on UC before and after optimisation, employing 16S rDNA sequencing, bile acid-targeted metabolomics, and transcriptome analysis to elucidate the potential mechanism of water-soluble baicalin; and the key genes and proteins implicated in this mechanism were verified through RT-PCR and western blotting.

RESULTS

A new form of baicalin present in the aqueous solution of S. baicalensis Georgi was isolated, and its structural characterisation showed that it was bound to magnesium ions (baicalin magnesium) and exhibited favorable water solubility. Baicalin magnesium offers enhanced therapeutic benefits over baicalin for UC treatment, which alleviated the inflammatory response and oxidative stress levels while improving intestinal mucosal damage. Further investigation of the mechanism revealed that baicalin magnesium could effectively regulate bile acid metabolism and maintain intestinal microecological balance in UC mice, and suppress the activation of the nuclear factor-kappa B and peroxisome proliferator-activated receptor α signalling pathways, thereby playing a therapeutic role.

CONCLUSIONS

Baicalin magnesium has good water solubility, which solves the bottleneck problem of water insolubility in the practical applications of baicalin. Moreover, baicalin magnesium exhibits therapeutic potential for UC significantly better than baicalin.

Novel fast dissolving freeze dried sublingual baicalin tablets for enhanced hepatoprotective effect: in-vitro characterization, cell viability, and in-vivo evaluation

Baicalin (BG), a natural product, has been used in the prevention and treatment of drug-induced liver injury (DILI); however, its poor solubility and extensive liver metabolism limit its pharmacological use. The aim of the present study was the formulation of fast-dissolving freeze-dried sublingual tablets (FFSTs) to increase BG dissolution, avoid first-pass metabolism, and overcome swallowing difficulties. FFSTs were prepared following a 23 factorial design. The effect of three independent variables namely matrix former, Maltodextrin, concentration (4%, and 6%), binder concentration (2%, and 3%), and binder type (Methocel E5, and Methocel E15) on the FFSTs' in-vitro disintegration time and percentage dissolution was studied along with other tablet characteristics. Differential scanning calorimetry, scanning electron microscopy, in-vitro HepG2 cell viability assay, and in-vivo characterization were also performed. F8 (6% Maltodextrin, 2% Mannitol, 2% Methocel E5), with desirability of 0.852, has been furtherly enhanced using 1%PEG (F10). F10 has achieved an in-vitro disintegration time of 41 secs, and 60.83% in-vitro dissolution after 2 min. Cell viability assay, in-vivo study in rats, and histopathological studies confirmed that pretreatment with F10 has achieved a significant hepatoprotective effect against acetaminophen-induced hepatotoxicity. The outcome of this study demonstrated that FFSTs may present a patient-friendly dosage form against DILI.

Intranasal Radioiodinated Ferulic Acid Polymeric Micelles as the First Nuclear Medicine Imaging Probe for ETRA Brain Receptor

INTRODUCTION

The aim of this work was to prepare a selective nuclear medicine imaging probe for the Endothelin 1 receptor A in the brain.

MATERIAL AND METHODS

Ferulic acid (an ETRA antagonist) was radiolabeled using 131I by direct electrophilic substitution method. The radiolabeled ferulic acid was formulated as polymeric micelles to allow intranasal brain delivery. Biodistribution was studied in Swiss albino mice by comparing brain uptake of 131I-ferulic acid after IN administration of 131I-ferulic acid polymeric micelles, IN administration of 131I-ferulic acid solution and IV administration of 131I-ferulic acid solution.

RESULTS

Successful radiolabeling was achieved with an RCY of 98 % using 200 μg of ferulic acid and 60 μg of CAT as oxidizing agents at pH 6, room temperature and 30 min reaction time. 131I-ferulic acid polymeric micelles were successfully formulated with the particle size of 21.63 nm and polydispersity index of 0.168. Radioactivity uptake in the brain and brain/blood uptake ratio for I.N 131I-ferulic acid polymeric micelles were greater than the two other routes at all periods.

CONCLUSION

Our results provide 131I-ferulic acid polymeric micelles as a hopeful nuclear medicine tracer for ETRA brain receptor.

Niosomal formulation of mefenamic acid for enhanced cancer targeting; preparation, characterization and biodistribution study using radiolabeling technique

BACKGROUND

This work aimed to prepare niosomal formulations of an anticancer agent [mefenamic acid (MEF)] to enhance its cancer targeting. 131I was utilized as a radiolabeling isotope to study the radio-kinetics of MEF niosomes.

METHODS

niosomal formulations were prepared by the ether injection method and assessed for entrapment efficiency (EE%), zeta potential (ZP), polydispersity index (PDI) and particle size (PS). MEF was labeled with 131I by direct electrophilic substitution reaction through optimization of radiolabeling-related parameters. In the radio-kinetic study, the optimal 131I-MEF niosomal formula was administered intravenously (I.V.) to solid tumor-bearing mice and compared to I.V. 131I-MEF solution as a control.

RESULTS

the average PS and ZP values of the optimal formulation were 247.23 ± 2.32 nm and - 28.3 ± 1.21, respectively. The highest 131I-MEF labeling yield was 98.7 ± 0.8%. The biodistribution study revealed that the highest tumor uptake of 131I-MEF niosomal formula and 131I-MEF solution at 60 min post-injection were 2.73 and 1.94% ID/g, respectively.

CONCLUSION

MEF-loaded niosomes could be a hopeful candidate in cancer treatment due to their potent tumor uptake. Such high targeting was attributed to passive targeting of the nanosized niosomes and confirmed by radiokinetic evaluation.

Liver-Targeting Composite Nanocarrier Delivery System Based on Chitosan Nanoparticles and Phospholipid Complexes

Liver fibrosis is mainly caused by excessive accumulation of extracellular matrix and structural changes in the liver, ultimately leading to cirrhosis if left untreated. Reducing hyaluronan synthesis by inhibiting hyaluronic acid deposition or regulating the expression of hyaluronic synthase can ameliorate liver fibrosis symptoms. In this study, we aimed to improve the bioavailability and liver-targeting capacity of hydroxymethyl coumarin (4-MU) using a newly developed phospholipid complex chitosan nanoparticle (4-MU PC/CNP) optimized using the Box-Behnken design. The composite nanocarrier delivery system was formulated using solvent evaporation technology, and formulation and process parameters were evaluated. Furthermore, 4-MU PC/CNPs and their pharmacokinetics were characterized. The established 4-MU PC/CNPs had an average particle size of 153.07 ± 0.29 nm, a polydispersity index value of 0.383, and a positive zeta potential of ∼35.4 mV. Compared with 4-MUs, 4-MU PC/CNPs exhibited significantly improved water solubility, faster plasma clearance and tissue distribution, and better liver targeting. Pharmacokinetic analysis showed that the oral bioavailability of 4-MU in 4-MU PC/CNPs was significantly higher than that of simple 4-MU. In conclusion, 4-MU PC improved drug lipid (oil-water distribution coefficient of 1.31 ± 0.03) and water solubilities (2.05 times the drug substance). 4-MU PC/CNPs significantly improved 4-MU oral bioavailability, representing a promising approach for enhancing drug solubility. This study demonstrates that the targeting parameters of 4-MU PC/CNPs in the liver were all greater than 1, indicating that they specifically targeted the liver, thereby potentially alleviating liver fibrosis.

Targeted delivery of nutraceuticals derived from food for the treatment of obesity and its related complications

Nutraceuticals which are abundant in foods have attracted much attention due to their bioactive activities of anti-obesity, anti-hyperlipidemia and anti-atherosclerosis. Unfortunately, the poor bioavailability severely undermines their envisioned benefits. Therefore, there is an urgent need to develop suitable delivery systems to promote the benefits of their biological activity. Targeted drug delivery system (TDDS) is a novel drug delivery system that can selectively concentrate drugs on targets in the body, improve the bioavailability of agents and reduce side effects. This emerging drug delivery system provides a new strategy for the treatment of obesity with nutraceuticals and would be a promising alternative to be widely used in the food field. This review summarizes the recent studies on the application in the targeted delivery of nutraceuticals for treating obesity and its related complications, especially the available receptors and their corresponding ligands for TDDS and the evaluation methods of the targeting ability.

Recent development in nanoencapsulation and delivery of natural bioactives through chitosan scaffolds for various biological applications

Nowadays, nano/micro-encapsulation as a pioneering technique may significantly improve the bioavailability and durability of Natural bioactives. For this purpose, chitosan as a bioactive cationic natural polysaccharide has been frequently used as a carrier because of its distinct chemical and biological properties, including polycationic nature, biocompatibility, and biodegradability. Moreover, polysaccharide-based nano/micro-formulations are a new and extensive trend in scientific research and development in the disciplines of biomedicine, bioorganic/ medicinal chemistry, pharmaceutics, agrochemistry, and the food industry. It promises a new paradigm in drug delivery systems and nanocarrier formulations. This review aims to summarize current developments in approaches for designing innovative chitosan micro/nano-matrix, with an emphasis on the encapsulation of natural bioactives. The special emphasis led to a detailed integrative scientific achievement of the functionalities and abilities for encapsulating natural bioactives and mechanisms regulated in vitro/in vivo release in various biological/physiological environments.

A Nano-Liposomal Formulation of Caffeic Acid Phenethyl Ester Modulates Nrf2 and NF-κβ Signaling and Alleviates Experimentally Induced Acute Pancreatitis in a Rat Model

The currently available management strategies for acute pancreatitis are inadequately effective which calls for exploration of new approaches to treat this condition. Caffeic acid phenethyl ester (CAPE) is a major bioactive constituent of honeybee propolis with promising therapeutic and preventive applications. However, its pharmaceutical potential and clinical use are hindered by its poor water solubility and limited plasma stability. In this study, we aimed to prepare, characterize and evaluate a CAPE-loaded nanoliposomal formulation to improve the efficacy of CAPE for the management of acute pancreatitis. The CAPE-loaded nanoliposomes (CAPE-loaded-NL) were prepared by a thin layer evaporation technique and were optimized using three edge activators. CAPE-loaded-NL were characterized for their vesicle size (VS), zeta potential (ZP), encapsulation efficiency (EE), polydispersity index (PDI), crystalline state and morphology. The protective effect of the optimal CAPE-loaded-NL was evaluated in a rat model of acute pancreatitis induced by administering a single intraperitoneal injection of L-ornithine. Oral pretreatment with CAPE-loaded-NL significantly counteracted ornithine-induced elevation in serum activities of pancreatic digestive enzymes and pancreatic levels of malondialdehyde, nuclear factor kappa B (NF-κB) p65, tumor necrosis factor-alpha, nitrite/nitrate, cleaved caspase-3 and myeloperoxidase activity. Moreover, pretreatment with CAPE-loaded-NL significantly reinstated the ornithine-lowered glutathione reductase activity, glutathione, nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 levels and ATP/ADP ratio, and potentiated the Bcl-2/Bax ratio in pancreatic tissue. CAPE-loaded-NL displayed superior antioxidant, anti-inflammatory and anti-apoptotic effects compared to free CAPE oral suspension and achieved a more potent correction of the derangements in serum amylase and pancreatic myeloperoxidase activities. The histological observations were in line with the biochemical findings. Our results suggest that CAPE-loaded-NL provide a promising interventional approach for acute pancreatitis mainly through the enhancement of the exerted antioxidant, anti-inflammatory and anti-apoptotic effects which may be mediated, at least in part, through modulation of Nrf2 and NF-κβ signaling.

Optimization, Characterization and In Vivo Evaluation of Mupirocin Nanocrystals for Topical Administration

Treatment of infectious skin conditions resulting from wounds and burns with topical antibiotics is challenging, particularly those caused by methicillin-resistant Staphylococcus aureus bacteria (MRSA). This is due to the formation of bacterial biofilms characterized by antimicrobial resistance. Mupirocin (MP), a widely used topical antibiotic, is active against gram-positive bacteria including MRSA. However, MP suffers from sub-optimal therapeutic efficacy due to its poor water-solubility and the significant rise in MP-resistant S. aureus. In this study, the physico-chemical characteristics of MP were modified through nanocrystallization to improve its therapeutic efficacy for the treatment of skin infections. Mupirocin-nanocrystals (MP-NC) were prepared using a nanoprecipitation technique and optimized using a D-optimal response surface design. The optimization of MP-NC produced ultra-small monodisperse spherical particles with a mean diameter of 70 nm and a polydispersity index of 0.2. The design resulted in two optimal MP-NC formulations that were evaluated by performing series of in vitro, ex vivo, microbiological, and in vivo studies. In-vitro results showed a 10-fold increase in the saturation solubility and a 9-fold increase in the dissolution rate of MP-NC. Ex vivo permeation studies, using pig ears skin, showed a 2-fold increase in the dermal deposition of MP-NC with the highest drug deposition occurring at 500-µm skin depth. Moreover, the optimal MP-NC formulations were lyophilized and incorporated into a 2% w/w cream. Microbiological studies revealed a 16-fold decrease in the minimum inhibitory concentration and the minimum bactericidal concentration of MP-NC. In vivo studies, using a rat excision burn wound model, demonstrated rapid and complete healing of infected burn wounds in rats treated with MP-NC cream in comparison to marketed Avoban ointment. Our results suggest that nanocrystallization of MP may provide an avenue through which higher levels of a topically applied MP can be permeated into the skin to reach relevant infectious areas and exert potential local antibacterial effects.

Macrophage membrane modified baicalin liposomes improve brain targeting for alleviating cerebral ischemia reperfusion injury

Baicalin (BA) has a good intervention effect on encephalopathy. In this study, macrophage membrane was modified on the surface of baicalin liposomes (BA-LP) by extrusion method. Macrophage membrane modified BA-LP (MM-BA-LP) was characterized by various analytical techniques, and evaluated for brain targeting. The results presented MM-BA-LP had better brain targeting compared with BA-LP. Pharmacokinetic experiments showed that MM-BA-LP improved pharmacokinetic parameters and increased the residence time of BA. Pharmacodynamic of middle cerebral artery occlusion (MCAO) rat model was studied to verify the therapeutic effect of MM-BA-LP on cerebral ischemia reperfusion injury (CIRI). The results showed that MM-BA-LP could significantly improve the neurological deficit, cerebral infarction volume and brain pathological state of MCAO rats compared with BA-LP. These results suggested that MM-BA-LP could significantly enhance the brain targeting and improve the circulation of BA in blood, and had a significantly better neuroprotective effect on MCAO rats than BA-LP.

Radiolabeling, biological distribution, docking and ADME studies of 99mTc-Ros as a promising natural tumor tracer

Rosmarinic acid (Ros) is one of phenolic metabolites with powerful potency as an anticancer agent, with different mechanisms to diminish the cancer cells. This current study represents radiolabeling of Ros with 99mTc using SnCl2 in pH4 for 15 min at 60 °C, The yield up to 92.2%. Biological evaluation in normal and cancer mice revealed the localization of the tracer in tumor tissue. Furthermore, docking and ADME (Absorption, Distribution, Metabolism, and Excretion) studies were performed, The resulted data clarifies the use of Ros as a promissing natural tracer.

Baicalin-loaded folic acid-modified albumin nanoparticles (FA-BSANPs/BA) induce autophagy in MCF-7 cells via ROS-mediated p38 MAPK and Akt/mTOR pathway

Background

Breast cancer is the most frequently occurring cancer among women. Baicalin has been shown to inhibit breast cancer proliferation, but poor aqueous solubility and unknown mechanism of action limit its application. This study aimed to investigate the antiproliferative effects of baicalin-loaded folic acid-modified albumin nanoparticles (FA-BSANPs/BA) in breast cancer MCF-7 cells and its relationship with autophagy and ROS-mediated p38 MAPK and Akt/mTOR signaling pathways. Cell viability was detected by MTT assay. Flow cytometry and fluorescence microscopy were used to detect cell cycle, apoptosis and autophagy. Western blot was used to detect protein expression.

Results

Compared with the control and free baicalin groups, FA-BSANPs/BA inhibited viability of MCF-7 cells and increased cells in S phase, apoptotic bodies, pro-apoptotic proteins, autophagy markers and autophagosomes. These effects could be reversed when combined with the autophagy inhibitor 3-methyladenine. FA-BSANPs/BA increased the levels of phosphorylated p38 MAPK, inhibited the levels of phosphorylated Akt and mTOR, and increased the level of ROS in MCF-7 cells. The effects of FA-BSANPs/BA could be reversed or enhanced using inhibitors of Akt, mTOR, p38 MAPK and ROS scavengers.

Conclusions

Encapsulation in folate albumin nanoparticles improved the antiproliferative activity of baicalin. FA-BSANPs/BA induced autophagy and apoptosis via ROS-mediated p38 MAPK and Akt/mTOR signaling pathways in human breast cancer cells.

Asialoglycoprotein Receptor-Targeted Superparamagnetic Perfluorooctylbromide Nanoparticles

Background

The decrease in asialoglycoprotein receptor (ASGPR) levels is observed in patients with chronic liver disease and liver tumor. The aim of our study was to develop ASGPR-targeted superparamagnetic perfluorooctylbromide nanoparticles (M-PFONP) and wonder whether this composite agent could target buffalo rat liver (BRL) cells in vitro and could improve R2^∗ value of the rat liver parenchyma after its injection in vivo.

Methods

GalPLL, a ligand of ASGPR, was synthesized by reductive amination. ASGPR-targeted M-PFOBNP was prepared by a film hydration method coupled with sonication. Several analytical methods were used to investigate the characterization and safety of the contrast agent in vitro. The in vivo MR T2^∗ mapping was performed to evaluate the enhancement effect in rat liver.

Results

The optimum concentration of Fe₃O₄ nanoparticles inclusion in GalPLL/M-PFOBNP was about 52.79 µg/mL, and the mean size was 285.6 ± 4.6 nm. The specificity of GalPLL/M-PFOBNP for ASGPR was confirmed by incubation experiment with fluorescence microscopy. The methyl thiazolyl tetrazolium (MTT) test showed that there was no significant difference in the optical density (OD) of cells incubated with all GalPLL/M-PFOBNP concentrations. Compared with M-PFOBNP, the increase in R2^∗ value of the rat liver parenchyma after GalPLL/M-PFOBNP injection was higher.

Conclusions

GalPLL/M-PFOBNP may potentially serve as a liver-targeted contrast agent for MR receptor imaging.

Pharmacological properties of baicalin on liver diseases: a narrative review

Baicalin is the main active component of Scutellaria baicalensis, widely used in traditional Chinese medicine thanks to its various pharmacological effects, such as anti-tumor, anti-inflammatory, and antibacterial properties, as well as cardiovascular, hepatic, and renal protective effect. Recently, the protective effects of baicalin on liver disease have received much more attention. Several studies showed that baicalin protects against several types of liver diseases including viral hepatitis, fatty liver disease, xenobiotic induced liver injury, cholestatic liver injury, and hepatocellular carcinoma, with a variety of pharmacological mechanisms. A comprehensive understanding of the mechanism of baicalin can provide a valuable reference for its clinical use, but up to now, no narrative review is available that summarizes the pharmacological effects of baicalin to clarify its potential use in the treatment of liver diseases. Therefore, this review summarizes the progress of baicalin research and the underlying mechanism in the treatment of various liver diseases, to promote further research and its clinical application.

Radiolabelling of nanomaterials for medical imaging and therapy

Nanomaterials offer unique physical, chemical and biological properties of interest for medical imaging and therapy. Over the last two decades, there has been an increasing effort to translate nanomaterial-based medicinal products (so-called nanomedicines) into clinical practice and, although multiple nanoparticle-based formulations are clinically available, there is still a disparity between the number of pre-clinical products and those that reach clinical approval. To facilitate the efficient clinical translation of nanomedicinal-drugs, it is important to study their whole-body biodistribution and pharmacokinetics from the early stages of their development. Integrating this knowledge with that of their therapeutic profile and/or toxicity should provide a powerful combination to efficiently inform nanomedicine trials and allow early selection of the most promising candidates. In this context, radiolabelling nanomaterials allows whole-body and non-invasive in vivo tracking by the sensitive clinical imaging techniques positron emission tomography (PET), and single photon emission computed tomography (SPECT). Furthermore, certain radionuclides with specific nuclear emissions can elicit therapeutic effects by themselves, leading to radionuclide-based therapy. To ensure robust information during the development of nanomaterials for PET/SPECT imaging and/or radionuclide therapy, selection of the most appropriate radiolabelling method and knowledge of its limitations are critical. Different radiolabelling strategies are available depending on the type of material, the radionuclide and/or the final application. In this review we describe the different radiolabelling strategies currently available, with a critical vision over their advantages and disadvantages. The final aim is to review the most relevant and up-to-date knowledge available in this field, and support the efficient clinical translation of future nanomedicinal products for in vivo imaging and/or therapy.

Optimization and Evaluation of Poly(lactide-co-glycolide) Nanoparticles for Enhanced Cellular Uptake and Efficacy of Paclitaxel in the Treatment of Head and Neck Cancer

The particle size (PS) and encapsulation efficiency (EE%) of drug-loaded nanoparticles (NPs) may inhibit their cellular uptake and lead to possible leakage of the drug into the systemic circulation at the tumor site. In this work, ultra-high paclitaxel-loaded poly(lactide-co-glycolide) NPs (PTX-PLGA-NPs) with ultra-small sizes were prepared and optimized by adopting the principles of quality by design (QbD) approach. The optimized PTX-PLGA-NPs showed ultra-small spherical particles of about 53 nm with EE% exceeding 90%, a relatively low polydispersity index (PDI) of 0.221, an effective surface charge of -10.1 mV, and a 10-fold increase in the in vitro drug release over 72 h relative to free drug. The cellular viability of pharynx carcinoma cells decreased by almost 50% in 24 h following treatment with optimized PTX-PLGA-NPs, compared to only 20% from the free drug. The intracellular uptake of PTX-PLGA-NPs was highly favored, and the antitumor activity of PTX was remarkably improved with a reduction in its half maximal inhibitory concentration (IC50), by almost 50% relative to free drug solution. These results suggest that the optimal critical formulation parameters, guided by QbD principles, could produce PLGA-NPs with remarkably high EE% and ultra-small PS, resulting in enhanced cellular uptake and efficacy of PTX.

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.