In vitro cell uptake evaluation of curcumin-loaded PCL/F68 nanoparticles for potential application in neuronal diseases

Polymeric nanoparticles decorated with fragmented chitosan as modulation systems for neuronal drug uptake

This study aimed to modify chitosan (CS) by gamma irradiation and use it as a surface coating of nanoparticles (NPs) fabricated of poly lactic-co-glycolic acid (PLGA) to create mostly biocompatible nanosystems that can transport drugs to neurons. Gamma irradiation produced irradiated CS (CSγ) with a very low molecular weight (15.2-19.2 kDa). Coating NPs-PLGA with CSγ caused significant changes in their Z potential, making it slightly positive (from -21.7 ± 2.8 mV to +7.1 ± 2.3 mV) and in their particle size (184.4 0.4 ± 7.9 nm to 211.9 ± 14.04 nm). However, these changes were more pronounced in NPs coated with non-irradiated CS (Z potential = +54.0 ± 1.43 mV, size = 348.1 ± 16.44 nm). NPs coated with CSγ presented lower cytotoxicity and similar internalization levels in SH-SY5Y neuronal cells than NPs coated with non-irradiated CS, suggesting higher biocompatibility. Highly biocompatible NPs are desirable as nanocarriers to deliver drugs to the brain, as they help maintain the structure and function of the blood-brain barrier. Therefore, the NPs developed in this study could be evaluated as drug-delivery systems for treating brain diseases.

Polyglutamine (PolyQ) Diseases: Navigating the Landscape of Neurodegeneration

Polyglutamine (polyQ) diseases are a group of inherited neurodegenerative disorders caused by expanded cytosine-adenine-guanine (CAG) repeats encoding proteins with abnormally expanded polyglutamine tract. A total of nine polyQ disorders have been identified, including Huntington's disease, six spinocerebellar ataxias, dentatorubral pallidoluysian atrophy (DRPLA), and spinal and bulbar muscular atrophy (SBMA). The diseases of this class are each considered rare, yet polyQ diseases constitute the largest group of monogenic neurodegenerative disorders. While each subtype of polyQ diseases has its own causative gene, certain pathologic molecular attributes have been implicated in virtually all of the polyQ diseases, including protein aggregation, proteolytic cleavage, neuronal dysfunction, transcription dysregulation, autophagy impairment, and mitochondrial dysfunction. Although animal models of polyQ disease are available helping to understand their pathogenesis and access disease-modifying therapies, there is neither a cure nor prevention for these diseases, with only symptomatic treatments available. In this paper, we analyze data from the CAS Content Collection to summarize the research progress in the class of polyQ diseases. We examine the publication landscape in the area in effort to provide insights into current knowledge advances and developments. We review the most discussed concepts and assess the strategies to combat these diseases. Finally, we inspect clinical applications of products against polyQ diseases with their development pipelines. The objective of this review is to provide a broad overview of the evolving landscape of current knowledge regarding the class of polyQ diseases, to outline challenges, and evaluate growth opportunities to further efforts in combating the diseases.

Development of 3D skin equivalents for application in photodynamic biostimulation therapy assays using curcumin nanocapsules

For decades, animal models have been the standard approach in drug research and development, as they are required by regulations in the transition from preclinical to clinical trials. However, there is growing ethical and scientific concern regarding these trials, as 80 % of the therapeutic potential observed in pre-clinical studies are often unable to be replicated, despite demonstrating efficacy and safety. In response to this, Tissue Engineering has emerged as a promising alternative that enables the treatment of various diseases through the production of biological models for advanced biological assays or through the direct development of tissue repairs or replacements. One of the promising applications of Tissue Engineering is the development of three-dimensional (3D) models for in vitro tests, replacing the need for in vivo animal models. In this study, 3D skin equivalents (TSE) were produced and used as an in vitro model to test photobiostimulation using curcumin-loaded nanocapsules. Photodynamic biostimulation therapy uses photodynamic processes to generate small amounts of reactive oxygen species (ROS), which can activate important biological effects such as cell differentiation, modulation of inflammatory processes and contribution to cell regeneration. The PLGA nanocapsules (NC) used in the study were synthesized through a preformed polymer deposition method, exhibiting particle size <200 nm, Zeta potential >|30| and polydispersity index between 0.5 and 0.3. Atomic force microscopy analyzes confirmed that the particle size was <200 nm, with a spherical morphology and a predominantly smooth and uniform surface. The NC biocompatibility assay did not demonstrate cytotoxicity for the concentrations tested (2.5-25 μg mL-1).The in vitro release assay showed a slow and sustained release characteristic of the nanocapsules, and cellular uptake assays indicated a significant increase in cellular internalization of the curcumin-loaded nanostructure. Monolayer photobiostimulation studies revealed an increase in cell viability of the HDFn cell line (viability 134 %-228 %) for all LED fluences employed at λ = 450 nm (150, 300, and 450 mJ cm-2). Additionally, the scratch assays, monitoring in vitro scar injury, demonstrated more effective effects on cell proliferation with the fluence of 300 mJ cm-2. Staining of TSE with hematoxylin and eosin showed the presence of cells with different morphologies, confirming the presence of fibroblasts and keratinocytes. Immunohistochemistry using KI-67 revealed the presence of proliferating cells in TSE after irradiation with LED λ = 450 nm (150, 300, and 450 mJ cm-2).

Microwave-Assisted, Solid-State Procedure to Covalently Conjugate Hyaluronic Acid to Curcumin: Validation of a Green Synthetic Protocol

A microwave-assisted esterification reaction to prepare hyaluronan-curcumin derivatives by employing a solvent-free process was developed. In particular, a solid-state strategy to react two molecules characterized by totally different solubility profiles was developed. Hyaluronic acid, a highly hydrosoluble polysaccharide, was reacted with hydrophobic and even water-unstable curcumin. Microwave (MW) irradiation was employed to activate the reaction between the two solid compounds through the direct interaction with them and to preserve the integrity of the sensitive curcumin species. This new protocol can be considered efficient, fast, and also eco-friendly, avoiding the employment of toxic organic bases and solvents. A cytotoxicity test suggested that the developed hyaluronan-curcumin conjugate (HA-CUR) could be considered a candidate for its implementation as a new material. In addition, preliminary studies revealed promising anti-inflammatory activity and open future perspectives of further investigation.

Nanotechnology in the diagnostic and therapy for Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder primarily characterized by β-amyloid plaque, intraneuronal tangles, significant neuronal loss and cognitive deficit. Treatment in the early stages of the disease is crucial for preventing or perhaps reversing the neurodegeneration in the AD cases. However, none of the current diagnostic procedures are capable of early diagnosis of AD. Further, the available treatments merely provide symptomatic alleviation in AD and do not address the underlying illness. Therefore, there is no permanent cure for AD currently. Better therapeutic outcomes need the optimum drug concentration in the central nervous system (CNS) by traversing blood-brain-barrier (BBB). Nanotechnology offers enormous promise to transform the treatment and diagnostics of neurodegenerative diseases. Nanotechnology based diagnostic tools, drug delivery systems and theragnostic are capable of highly sensitive molecular detection, effective drug targeting and their combination. Significant work has been done in this area over the last decade and prospective results have been obtained in AD therapy. This review explores the various applications of nanotechnology in addressing the varied facets of AD, ranging from early detection to therapeutic interventions. This review also looks at how nanotechnology can help with the development of disease-modifying medicines, such as the delivery of anti-amyloid, anti-tau, cholinesterase inhibitors, antioxidants and hormonal drugs. In conclusion, this paper discusses the role of nanotechnology in the early detection of AD, effective drug targeting to the CNS and theragnostic applications in the management of AD.

pH-sensitive liposomes bearing a chemotherapeutic agent and a natural apoptosis modulator for effective intracellular delivery to the solid tumor

The intracellular delivery of the drug to the solid tumor is a major challenge in the treatment of solid tumors. This project aims to increase cytosolic drug delivery using the endosomal escape of drugs. Topotecan (TPT) and capsaicin were used for the treatment of solid tumors. The pH-dependent conversion of active lactone form to inactive carboxylic form is a major problem of TPT that limits its therapeutic use. Liposomal encapsulation of TPT improved the stability of active lactone form and increased the therapeutic efficacy of TPT. Endosomal degradation of liposomes may reduce the content in the target cells. To solve these problems, pH-sensitive liposomes (pSLPs) were developed which improved the intracellular drug delivery by the endosomal escape of drugs. The liposomes (LPs) bearing the drug(s) were prepared using the cast film method and optimized for various formulation and process variables using the Design-Expert 7 software by employing the Box-Behnken design (BBD). The developed hyaluronic acid (HA)-conjugated pSLPs (HA-pSLPs) displayed a vesicle size of 166.5 ± 2.31 nm, zeta potential - 30.53 ± 0.91, and entrapment efficiency of 44.39 ± 1.78%, and 73.48 ± 2.15% for TPT and CAP, respectively. HA-pSLPs displayed better cytotoxicity in comparison to free drugs either single or in combination on the MCF-7 cell line. The apoptosis and cellular uptake of HA-pSLPs were increased ⁓ 4.45-fold and ⁓ 6.95-fold as compared to unconjugated pSLPs, respectively. The pharmacokinetic studies in Balb/c mice demonstrated that HA-pSLPs increased the half-life, MRT, and AUC in comparison to the free drug solution. The HA-pSLPs formulation has shown remarkable tumor regression as compared to PpSLPs, pSLPs, and free drug combinations. These results demonstrated that TPT- and CAP-loaded HA-pSLPs offer a potential platform for targeted drug delivery to solid tumors.

Development of a Polymeric Pharmacological Nanocarrier System as a Potential Therapy for Spinocerebellar Ataxia Type 7

Spinocerebellar ataxia type 7 (SCA7) is an autosomal-dominant inherited disease characterized by progressive ataxia and retinal degeneration. SCA7 belongs to a group of neurodegenerative diseases caused by an expanded CAG repeat in the disease-causing gene, resulting in aberrant polyglutamine (polyQ) protein synthesis. PolyQ ataxin-7 is prone to aggregate in intracellular inclusions, perturbing cellular processes leading to neuronal death in specific regions of the central nervous system (CNS). Currently, there is no treatment for SCA7; however, a promising approach successfully applied to other polyQ diseases involves the clearance of polyQ protein aggregates through pharmacological activation of autophagy. Nonetheless, the blood-brain barrier (BBB) poses a challenge for delivering drugs to the CNS, limiting treatment effectiveness. This study aimed to develop a polymeric nanocarrier system to deliver therapeutic agents across the BBB into the CNS. We prepared poly(lactic-co-glycolic acid) nanoparticles (NPs) modified with Poloxamer188 and loaded with rapamycin to enable NPs to activate autophagy. We demonstrated that these rapamycin-loaded NPs were successfully taken up by neuronal and glial cells, demonstrating high biocompatibility without adverse effects. Remarkably, rapamycin-loaded NPs effectively cleared mutant ataxin-7 aggregates in a SCA7 glial cell model, highlighting their potential as a therapeutic approach to fight SCA7 and other polyQ diseases.

Curcumin in exfoliated layered double hydroxide nanoparticles: Pre-clinical evaluation as lung cancer nanomedicine

Rationally designed ∼ 100 nm sized curcumin (CRC) loaded exfoliated layered double hydroxide nanoparticles (X-LDH/CRC-NPs) have been tested for its suitability as nanomedicine in non-small cell lung cancer (NSCLC) cell lines (A549 and NCI-H460) resulting enhanced apoptosis. Preclinical evaluation on A549 tumor bearing nude mouse model confirmed that such a well-designed X-LDH/CRC NPs would be highly advantageous for treating lung cancers.

PEG 400:Trehalose Coating Enhances Curcumin-Loaded PLGA Nanoparticle Internalization in Neuronal Cells

This work proposes a combination of polyethylene glycol 400 (PEG) and trehalose as a surface modification approach to enhance PLGA-based nanoparticles as a drug carrier for neurons. PEG improves nanoparticles' hydrophilicity, and trehalose enhances the nanoparticle's cellular internalization by inducing a more auspicious microenvironment based on inhibiting cell surface receptor denaturation. To optimize the nanoprecipitation process, a central composite design was performed; nanoparticles were adsorbed with PEG and trehalose. PLGA nanoparticles with diameters smaller than 200 nm were produced, and the coating process did not considerably increase their size. Nanoparticles entrapped curcumin, and their release profile was determined. The nanoparticles presented a curcumin entrapment efficiency of over 40%, and coated nanoparticles reached 60% of curcumin release in two weeks. MTT tests and curcumin fluorescence, with confocal imaging, were used to assess nanoparticle cytotoxicity and cell internalization in SH-SY5Y cells. Free curcumin 80 µM depleted the cell survival to 13% at 72 h. Contrariwise, PEG:Trehalose-coated curcumin-loaded and non-loaded nanoparticles preserved cell survival at 76% and 79% under the same conditions, respectively. Cells incubated with 100 µM curcumin or curcumin nanoparticles for 1 h exhibited 13.4% and 14.84% of curcumin's fluorescence, respectively. Moreover, cells exposed to 100 µM curcumin in PEG:Trehalose-coated nanoparticles for 1 h presented 28% fluorescence. In conclusion, PEG:Trehalose-adsorbed nanoparticles smaller than 200 nm exhibited suitable neural cytotoxicity and increased cell internalization proficiency.

Nanoparticles Based on Chondroitin Sulfate from Tuna Heads and Chitooligosaccharides for Enhanced Water Solubility and Sustained Release of Curcumin

This study aimed to separate chondroitin sulfate (CS) from the heads of skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacares), by-products derived from canned tuna processing, via a biological process. The use of 1% w/w papain and an incubation time of 48 h resulted in a degree of hydrolysis of 93.75 ± 2.94% and a CS content of 59.53 ± 1.77 mg/100 g. The FTIR spectra of extracted CS products exhibited identical functional groups found in commercially available CS. The molecular weights of CS extracted from skipjack and yellowfin tuna heads were 11.0 kDa and 7.7 kDa, respectively. Subsequently, a CH:CS ratio of 3:2 for CS and chitooligosaccharides (CH) was chosen as the optimal ratio for the preparation of spherical nanoparticles, with %EE, mean particle size, PDI, and zeta potential values of 50.89 ± 0.66%, 128.90 ± 3.29 nm, 0.27 ± 0.04, and -12.47 ± 2.06, respectively. The CU content was enhanced to 127.21 ± 1.66 μg/mL. The release of CU from this particular nanosystem involved mainly a drug diffusion mechanism, with a burst release in the first 3 h followed by a sustained release of CU over 24 h. The DPPH and ABTS scavenging activity results confirmed the efficient encapsulation of CU into CHCS nanoparticles. This study will provide a theoretical basis for CS derived from tuna head cartilages to be used as a functional component with specific functional properties in food and biomedical applications.

Cumulative antitumor effect of bismuth lipophilic nanoparticles and cetylpyridinium chloride in inhibiting the growth of lung cancer

OBJECTIVE

To determine the combined antitumor effect of bismuth lipophilic nanoparticles (BisBAL NP) and cetylpyridinium chloride (CPC) on human lung tumor cells.

MATERIAL AND METHODS

The human lung tumor cells A549 were exposed to 1-100 µM BisBAL NP or CPC, either separately or in a 1:1 combination. Cell viability was measured with the PrestoBlue assay, the LIVE/DEAD assay, and fluorescence microscopy. The integrity and morphology of cellular microtubules were analyzed by immunofluorescence.

RESULTS

A 24-h exposure to 1 µM solutions reduced A549 growth with 21.5% for BisBAL NP, 70.5% for CPC, and 92.4% for the combination (p < 0.0001), while a 50 µM BisBAL NP/CPC mixture inhibited cell growth with 99% (p < 0.0001). BisBAL NP-curcumin conjugates were internalized within 30 min of exposure and could be traced within the nucleus of tumor cells within 2 h. BisBAL NP, but not CPC, interfered with microtubule organization, thus interrupting cell replication, similar to the action mechanism of docetaxel.

CONCLUSION

The growth inhibition of A549 human tumor cells by BisBAL NP and CPC was cumulative as of 1 µM. The BisBAL NP/CPC combination may constitute an innovative and cost-effective alternative for treating human lung cancer.

Repositioning of drugs for Parkinson's disease and pharmaceutical nanotechnology tools for their optimization

Parkinson's disease (PD) significantly affects patients' quality of life and represents a high economic burden for health systems. Given the lack of safe and effective treatments for PD, drug repositioning seeks to offer new medication alternatives, reducing research time and costs compared to the traditional drug development strategy. This review aimed to collect evidence of drugs proposed as candidates to be reused in PD and identify those with the potential to be reformulated into nanocarriers to optimize future repositioning trials. We conducted a detailed search in PubMed, Web of Science, and Scopus from January 2015 at the end of 2021, with the descriptors "Parkinson's disease" and "drug repositioning" or "drug repurposing". We identified 28 drugs as potential candidates, and six of them were found in repositioning clinical trials for PD. However, a limitation of many of these drugs to achieve therapeutic success is their inability to cross the blood-brain barrier (BBB), as is the case with nilotinib, which has shown promising outcomes in clinical trials. We suggest reformulating these drugs in biodegradable nanoparticles (NPs) based on lipids and polymers to perform future trials. As a complementary strategy, we propose functionalizing the NPs surface by adding materials to the surface layer. Among other advantages, functionalization can promote efficient crossing through the BBB and improve the affinity of NPs towards certain brain regions. The main parameters to consider for the design of NPs targeting the central nervous system are highlighted, such as size, PDI, morphology, drug load, and Z potential. Finally, current advances in the use of NPs for Parkinson's disease are cited.

Antioxidant Effect of Nanoparticles Composed of Zein and Orange (Citrus sinensis) Extract Obtained by Ultrasound-Assisted Extraction

In the present research, an orange extract (OE) was obtained and encapsulated in a zein matrix for its subsequent physicochemical characterization and evaluation of its antioxidant capacity. The OE consists of phenolic compounds and flavonoids extracted from orange peel (Citrus sinensis) by ultrasound-assisted extraction (UAE). The results obtained by dynamic light scattering (DLS) and scanning electron microscopy (SEM) indicated that zein nanoparticles with orange extract (NpZOE) presented a nanometric size and spherical shape, presenting a hydrodynamic diameter of 159.26 ± 5.96 nm. Furthermore, ζ-potential evolution and Fourier transform infrared spectroscopy (FTIR) techniques were used to evaluate the interaction between zein and OE. Regarding antioxidant activity, ABTS and DPPH assays indicated no significant differences at high concentrations of orange peel extract and NpZOE; however, NpZOE was more effective at low concentrations. Although this indicates that ultrasonication as an extraction method effectively obtains the phenolic compounds present in orange peels, the nanoprecipitation method under the conditions used allowed us to obtain particles in the nanometric range with positive ζ-potential. On the other hand, the antioxidant capacity analysis indicated a high antioxidant capacity of both OE and the NpZOE. This study presents the possibility of obtaining orange extracts by ultrasound and coupling them to zein-based nanoparticulate systems to be applied as biomedical materials functionalized with antioxidant substances of pharmaceutical utility.

New Perspectives of Gene Therapy on Polyglutamine Spinocerebellar Ataxias: From Molecular Targets to Novel Nanovectors

Seven of the most frequent spinocerebellar ataxias (SCAs) are caused by a pathological expansion of a cytosine, adenine and guanine (CAG) trinucleotide repeat located in exonic regions of unrelated genes, which in turn leads to the synthesis of polyglutamine (polyQ) proteins. PolyQ proteins are prone to aggregate and form intracellular inclusions, which alter diverse cellular pathways, including transcriptional regulation, protein clearance, calcium homeostasis and apoptosis, ultimately leading to neurodegeneration. At present, treatment for SCAs is limited to symptomatic intervention, and there is no therapeutic approach to prevent or reverse disease progression. This review provides a compilation of the experimental advances obtained in cell-based and animal models toward the development of gene therapy strategies against polyQ SCAs, providing a discussion of their potential application in clinical trials. In the second part, we describe the promising potential of nanotechnology developments to treat polyQ SCA diseases. We describe, in detail, how the design of nanoparticle (NP) systems with different physicochemical and functionalization characteristics has been approached, in order to determine their ability to evade the immune system response and to enhance brain delivery of molecular tools. In the final part of this review, the imminent application of NP-based strategies in clinical trials for the treatment of polyQ SCA diseases is discussed.

A comprehensive review of the therapeutic potential of curcumin nanoformulations

Today, due to the prevalence of various diseases such as the novel coronavirus (SARS-CoV-2), diabetes, central nervous system diseases, cancer, cardiovascular disorders, and so on, extensive studies have been conducted on therapeutic properties of natural and synthetic agents. A literature review on herbal medicine and commercial products in the global market showed that curcumin (Cur) has many therapeutic benefits compared to other natural ingredients. Despite the unique properties of Cur, its use in clinical trials is very limited. The poor biopharmaceutical properties of Cur such as short half-life in plasma, low bioavailability, poor absorption, rapid metabolism, very low solubility (at acidic and physiological pH), and the chemical instability in body fluids are major concerns associated with the clinical applications of Cur. Recently, nanoformulations are emerging as approaches to develop and improve the therapeutic efficacy of various drugs. Many studies have shown that Cur nanoformulations have tremendous therapeutic potential against various diseases such as SARS-CoV-2, cancer, inflammatory, osteoporosis, and so on. These nanoformulations can inhibit many diseases through several cellular and molecular mechanisms. However, successful long-term clinical results are required to confirm their safety and clinical efficacy. The present review aims to update and explain the therapeutic potential of Cur nanoformulations.

Non-Ionic Surfactants for Stabilization of Polymeric Nanoparticles for Biomedical Uses

Surfactants are essential in the manufacture of polymeric nanoparticles by emulsion formation methods and to preserve the stability of carriers in liquid media. The deposition of non-ionic surfactants at the interface allows a considerable reduction of the globule of the emulsion with high biocompatibility and the possibility of oscillating the final sizes in a wide nanometric range. Therefore, this review presents an analysis of the three principal non-ionic surfactants utilized in the manufacture of polymeric nanoparticles; polysorbates, poly(vinyl alcohol), and poloxamers. We included a section on general properties and uses and a comprehensive compilation of formulations with each principal non-ionic surfactant. Then, we highlight a section on the interaction of non-ionic surfactants with biological barriers to emphasize that the function of surfactants is not limited to stabilizing the dispersion of nanoparticles and has a broad impact on pharmacokinetics. Finally, the last section corresponds to a recommendation in the experimental approach for choosing a surfactant applying the systematic methodology of Quality by Design.

Synthesis of New Water Soluble β-Cyclodextrin@Curcumin Conjugates and In Vitro Safety Evaluation in Primary Cultures of Rat Cortical Neurons

Self-aggregation of Curcumin (Cur) in aqueous biological environment decreases its bioavailability and in vivo therapeutic efficacy, which hampers its clinical use as candidate for reducing risk of neurodegenerative diseases. Here, we focused on the design of new Cur- β-Cyclodextrin nanoconjugates to improve the solubility and reduce cell toxicity of Cur. In this study, we described the synthesis, structural characterization, photophysical properties and neuron cell toxicity of two new water soluble β-CD/Cur nanoconjugates as new strategy for reducing risks of neurodegenerative diseases. Cur was coupled to one or two β-CD molecules via triazole rings using CuAAC click chemistry strategy to yield β-CD@Cur and (β-CD)₂@Cur nanoconjugates, respectively. The synthesized nanoconjugates were found to be able to self-assemble in aqueous condition and form nano-aggregates of an average diameter size of around 35 and 120 nm for β-CD@Cur and (β-CD)₂@Cur, respectively. The photophysical properties, water solubility and cell toxicity on rat embryonic cortical neurons of the designed nanoconjugates were investigated and compared to that of Cur alone. The findings revealed that both new nanoconjugates displayed better water solubility and in vitro biocompatibility than Cur alone, thus making it possible to envisage their use as future nano-systems for the prevention or risk reduction of neurodegenerative diseases.

Curcumin Loaded and Co-loaded Nanosystems: A Review from a Biological Activity Enhancement Perspective

BACKGROUND

Curcumin is a natural phenolic compound exhibiting multiple bioactivities that have been evaluated in vitro, in vivo as well as through clinical studies in humans. Some of them include antimicrobial, antioxidant, anti-inflammatory, and central nervous system protective effects. Further, curcumin is generally recognized as a safe substance because of its low toxicity. However, its molecular structure is susceptible to changes in pH, oxidation, photodegradation, low aqueous solubility, and biotransformation compromising its bioavailability; these drawbacks are successfully addressed through nanotechnology.

OBJECTIVE

The present review systematizes findings on the enhancement of curcumin's beneficial effects when it is loaded and co-loaded into different types of nanosystems covering liposomes, polymeric and solid-lipid nanoparticles, nanostructured lipid carrier, lipid-polymeric hybrids, self- -assembled and protein-based core-shell systems in relation to its antimicrobial, antioxidant, anti-inflammatory and central nervous system protective bioactivities.

CONCLUSION

Curcumin is a versatile molecule capable of exerting antimicrobial, antioxidant, anti- inflammatory, and central nervous system protective effects in an enhanced manner using the possibilities offered by the nanotechnology-based approach. Its enhanced bioactivities are associated with increments in solubility, stability, bioavailability, as well as in improved intracellular uptake and cell internalization. These advantages, in addition to curcumin's low toxicity, indicate the potential of curcumin to be loaded and co-loaded into nanosystems capable of providing a controlled release and targeted administration.

Curcumin-Loaded Nanoparticles Based on Amphiphilic Hyaluronan-Conjugate Explored as Targeting Delivery System for Neurodegenerative Disorders

Identification of molecules able to promote neuroprotective mechanisms can represent a promising therapeutic approach to neurodegenerative disorders including Huntington's disease. Curcumin is an antioxidant and neuroprotective agent, even though its efficacy is limited by its poor absorption, rapid metabolism, systemic elimination, and limited blood-brain barrier (BBB) permeability. Herein, we report on novel biodegradable curcumin-containing nanoparticles to favor the compound delivery and potentially enhance its brain bioavailability. The prepared hyaluronan-based materials able to self-assemble in stable spherical nanoparticles, consist of natural fatty acids chemically conjugated to the natural polysaccharide. The aim of this study is to provide a possible effective delivery system for curcumin with the expectation that, after having released the drug at the specific site, the biopolymer can degrade to nontoxic fragments before renal excretion, since all the starting materials are provided by natural resource. Our findings demonstrate that curcumin-encapsulated nanoparticles enter the cells and reduce their susceptibility to apoptosis in an in vitro model of Huntington's disease.

A Reevaluation of Chitosan-Decorated Nanoparticles to Cross the Blood-Brain Barrier

The blood-brain barrier (BBB) is a sophisticated and very selective dynamic interface composed of endothelial cells expressing enzymes, transport systems, and receptors that regulate the passage of nutrients, ions, oxygen, and other essential molecules to the brain, regulating its homeostasis. Moreover, the BBB performs a vital function in protecting the brain from pathogens and other dangerous agents in the blood circulation. Despite its crucial role, this barrier represents a difficult obstacle for the treatment of brain diseases because many therapeutic agents cannot cross it. Thus, different strategies based on nanoparticles have been explored in recent years. Concerning this, chitosan-decorated nanoparticles have demonstrated enormous potential for drug delivery across the BBB and treatment of Alzheimer's disease, Parkinson's disease, gliomas, cerebral ischemia, and schizophrenia. Our main objective was to highlight the high potential of chitosan adsorption to improve the penetrability through the BBB of nanoformulations for diseases of CNS. Therefore, we describe the BBB structure and function, as well as the routes of chitosan for crossing it. Moreover, we define the methods of decoration of nanoparticles with chitosan and provide numerous examples of their potential utilization in a variety of brain diseases. Lastly, we discuss future directions, mentioning the need for extensive characterization of proposed nanoformulations and clinical trials for evaluation of their efficacy.

Curcumin-loaded poly-ε-caprolactone nanoparticles show antioxidant and cytoprotective effects in the presence of reactive oxygen species

Interest in novel delivery systems that improve the cytoprotective and antioxidant effects of natural drugs has been explored recently due to the increase in the incidence of chronic diseases in which oxidation mechanisms are involved. Curcumin is a phenolic compound recently shown to be clinically significant due to its anti-inflammatory, anticancer, and antioxidant properties. However, this molecule possesses a low bioavailability and a high degradation rate in the presence of light. Therefore, we prepared nanoparticles of poly-ε-caprolactone and Pluronic® F-68 as a stabilizer and loaded these with curcumin (Cur–PCL nanoparticles) for antioxidant and cytoprotective applications. The nanoparticles did not induce cell death, but they did reduce cell proliferation without affecting cell migration and cell adhesion. Interestingly, Cur–PCL and poly-ε-caprolactone nanoparticles reduced the oxidative stress induced by hydrogen peroxide and presented a cytoprotective effect. Remarkably, poly-ε-caprolactone nanoparticles showed a decrement of 30% in reactive oxygen species presence compared to the positive control. The decrease of reactive oxygen species derived from the administration of poly-ε-caprolactone nanoparticles could be attributed to the presence of Pluronic® F-68. Taken together, these data indicated that these nanoparticles might have a clinical application in disorders related to reactive oxygen species formation.

Therapeutic Applications of Curcumin Nanomedicine Formulations in Cardiovascular Diseases

Cardiovascular diseases (CVD) compromises a group of heart and blood vessels disorders with high impact on human health and wellbeing. Curcumin (CUR) have demonstrated beneficial effects on these group of diseases that represent a global burden with a prevalence that continues increasing progressively. Pre- and clinical studies have demonstrated the CUR effects in CVD through its anti-hypercholesterolemic and anti-atherosclerotic effects and its protective properties against cardiac ischemia and reperfusion. However, the CUR therapeutic limitation is its bioavailability. New CUR nanomedicine formulations are developed to solve this problem. The present article aims to discuss different studies and approaches looking into the promising role of nanotechnology-based drug delivery systems to deliver CUR and its derivatives in CVD treatment, with an emphasis on their formulation properties, experimental evidence, bioactivity, as well as challenges and opportunities in developing these systems.

Curcumin's Nanomedicine Formulations for Therapeutic Application in Neurological Diseases

The brain is the body's control center, so when a disease affects it, the outcomes are devastating. Alzheimer's and Parkinson's disease, and multiple sclerosis are brain diseases that cause a large number of human deaths worldwide. Curcumin has demonstrated beneficial effects on brain health through several mechanisms such as antioxidant, amyloid β-binding, anti-inflammatory, tau inhibition, metal chelation, neurogenesis activity, and synaptogenesis promotion. The therapeutic limitation of curcumin is its bioavailability, and to address this problem, new nanoformulations are being developed. The present review aims to summarize the general bioactivity of curcumin in neurological disorders, how functional molecules are extracted, and the different types of nanoformulations available.

Development and Evaluation of Alginate Membranes with Curcumin-Loaded Nanoparticles for Potential Wound-Healing Applications

Non-biodegradable materials with a low swelling capacity and which are opaque and occlusive are the main problems associated with the clinical performance of some commercially available wound dressings. In this work, a novel biodegradable wound dressing was developed by means of alginate membrane and polycaprolactone nanoparticles loaded with curcumin for potential use in wound healing. Curcumin was employed as a model drug due to its important properties in wound healing, including antimicrobial, antifungal, and anti-inflammatory effects. To determine the potential use of wound dressing, in vitro, ex vivo, and in vivo studies were carried out. The novel membrane exhibited the diverse functional characteristics required to perform as a substitute for synthetic skin, such as a high capacity for swelling and adherence to the skin, evidence of pores to regulate the loss of transepidermal water, transparency for monitoring the wound, and drug-controlled release by the incorporation of nanoparticles. The incorporation of the nanocarriers aids the drug in permeating into different skin layers, solving the solubility problems of curcumin. The clinical application of this system would cover extensive areas of mixed first- and second-degree wounds, without the need for removal, thus decreasing the patient's discomfort and the risk of altering the formation of the new epithelium.