Preparation of curcumin-poly (allyl amine) hydrochloride based nanocapsules: Piperine in nanocapsules accelerates encapsulation and release of curcumin and effectiveness against colon cancer cells

Smart co-delivery of plasmid DNA and doxorubicin using MCM-chitosan-PEG polymerization functionalized with MUC-1 aptamer against breast cancer

This study introduces an innovative co-delivery approach using the MCM-co-polymerized nanosystem, integrating chitosan and polyethylene glycol, and targeted by the MUC-1 aptamer (MCM@CS@PEG-APT). This system enables simultaneous delivery of the GFP plasmid and doxorubicin (DOX). The synthesis of the nanosystem was thoroughly characterized at each step, including FTIR, XRD, BET, DLS, FE-SEM, and HRTEM analyses. The impact of individual polymers (chitosan and PEG) on payload retardation was compared to the co-polymerized MCM@CS@PEG conjugation. Furthermore, the DOX release mechanism was investigated using various kinetic models. The nanosystem's potential for delivering GFP plasmid and DOX separately and simultaneously was assessed through fluorescence microscopy and flow cytometry. The co-polymerized nanosystem exhibited superior payload entrapment (1:100 ratio of Plasmid:NPs) compared to separately polymer-coated counterparts (1:640 ratio of Plasmid:NPs). Besides, the presence of pH-sensitive chitosan creates a smart nanosystem for efficient DOX and GFP plasmid delivery into tumor cells, along with a Higuchi model pattern for drug release. Toxicity assessments against breast tumor cells also indicated reduced off-target effects compared to pure DOX, introducing it as a promising candidate for targeted cancer therapy. Cellular uptake findings demonstrated the nanosystem's ability to deliver GFP plasmid and DOX separately into MCF-7 cells, with rates of 32% and 98%, respectively. Flow cytometry results confirmed efficient co-delivery, with 42.7% of cells showing the presence of both GFP-plasmid and DOX, while 52.2% exclusively contained DOX. Overall, our study explores the co-delivery potential of the MCM@CS@PEG-APT nanosystem in breast cancer therapy. This system's ability to co-deliver multiple agents preciselyopens new avenues for targeted therapeutic strategies.

Preparation and characterization of a curcumin nanoemulsion gel for the effective treatment of mycoses

Fungal infections of skin including mycoses are one of the most common infections in skin or skins. Mycosis is caused by dermatophytes, non-dermatophyte moulds and yeasts. Various studies show different drugs to treat mycoses, yet there is need to treat it with applied drugs delivery. This study was designed to prepare a bio curcumin (CMN) nanoemulsion (CMN-NEs) for transdermal administration to treat mycoses. The self-nanoemulsification approach was used to prepare a nanoemulsion (NE), utilizing an oil phase consisting of Cremophor EL 100 (Cre EL), glyceryl monooleate (GMO), and polyethylene glycol 5000 (PEG 5000). Particle size (PS), polydispersity index (PDI), zeta potential (ZP), Fourier transform infrared (FTIR) spectrophotometric analysis, and morphological analyses were performed to evaluate the nanoemulsion (NE). The in vitro permeation of CMN was investigated using a modified vertical diffusion cell with an activated dialysis membrane bag. Among all the formulations, a stable, spontaneously produced nanoemulsion was determined with 250 mg of CMN loaded with 10 g of the oil phase. The average droplet size, ZP, and PDI of CMN-NEs were 90.0 ± 2.1 nm, - 7.4 ± 0.4, and 0.171 ± 0.03 mV, respectively. The release kinetics of CMN differed from zero order with a Higuchi release profile as a result of nanoemulsification, which also significantly increased the flux of CMN permeating from the hydrophilic matrix gel. Overall, the prepared nanoemulsion system not only increased the permeability of CMN but also protected it against chemical deterioration. Both CMN-ME (24.0 ± 0.31 mm) and CMN-NE gel (29.6 ± 0.25 mm) had zones of inhibition against Candida albicans that were significantly larger than those of marketed Itrostred gel (21.5 ± 0.34 mm). The prepared CMN-NE improved the bioavailability, better skin penetration, and the CMN-NE gel enhanced the release of CMN from the gel matrix on mycotic patients.

Curcumin in cancer therapy: Exploring molecular mechanisms and overcoming clinical challenges

Cancer poses a significant global health burden, necessitating the widespread use of chemotherapy and radiotherapy as conventional frontline interventions. Although targeted therapy and immunotherapy have shown remarkable advancements, the challenges of resistance development and severe side effects persist in cancer treatment. Consequently, researchers have actively sought more effective alternatives with improved safety profiles. In recent years, curcumin, a natural polyphenolic phytoalexin, has garnered considerable attention due to its broad spectrum of biological effects. This concise review provides valuable insights into the role of curcumin in cancer therapy, with a focus on elucidating its molecular mechanisms in inducing programmed cell death of tumor cells and suppressing tumor cell metastasis potential. Additionally, we discuss the challenges associated with the clinical application of curcumin and explore current endeavors aimed at overcoming these limitations. By shedding light on the promising potential of curcumin, this review contributes to the advancement of cancer treatment strategies.

Encapsulation of Polyphenolic Compounds Based on Hemicelluloses to Enhance Treatment of Inflammatory Bowel Diseases and Colorectal Cancer

Inflammatory bowel diseases (IBD) and colorectal cancer (CRC) are difficult to cure, and available treatment is associated with troubling side effects. In addition, current therapies have limited efficacy and are characterized by high costs, and a large segment of the IBD and CRC patients are refractive to the treatment. Moreover, presently used anti-IBD therapies in the clinics are primarily aimed on the symptomatic control. That is why new agents with therapeutic potential against IBD and CRC are required. Currently, polyphenols have received great attention in the pharmaceutical industry and in medicine due to their health-promoting properties. They may exert anti-inflammatory, anti-oxidative, and anti-cancer activity, via inhibiting production of pro-inflammatory cytokines and enzymes or factors associated with carcinogenesis (e.g., matrix metalloproteinases, vascular endothelial growth factor), suggesting they may have therapeutic potential against IBD and CRC. However, their use is limited under both processing conditions or gastrointestinal interactions, reducing their stability and hence their bioaccessibility and bioavailability. Therefore, there is a need for more effective carriers that could be used for encapsulation of polyphenolic compounds. In recent years, natural polysaccharides have been proposed for creating carriers used in the synthesis of polyphenol encapsulates. Among these, hemicelluloses are particularly noteworthy, being characterized by good biocompatibility, biodegradation, low immunogenicity, and pro-health activity. They may also demonstrate synergy with the polyphenol payload. This review discusses the utility and potential of hemicellulose-based encapsulations of polyphenols as support for treatment of IBD and CRC.

Therapeutic potential and limitations of curcumin as antimetastatic agent

Treatment of metastatic cancer is one of the biggest challenges in anticancer therapy. Curcumin is interesting nature polyphenolic compound with unique biological and medicinal effects, including repression of metastases. High impact studies imply that curcumin can modulate the immune system, independently target various metastatic signalling pathways, and repress migration and invasiveness of cancer cells. This review discusses the potential of curcumin as an antimetastatic agent and describes potential mechanisms of its antimetastatic activity. In addition, possible strategies (curcumin formulation, optimization of the method of administration and modification of its structure motif) to overcome its limitation such as low solubility and bioactivity are also presented. These strategies are discussed in the context of clinical trials and relevant biological studies.

An Updated Review on the Role of Nanoformulated Phytochemicals in Colorectal Cancer

The most common cancer-related cause of death worldwide is colorectal cancer. It is initiated with the formation of polyps, which further cause the development of colorectal cancer in multistep phases. Colorectal cancer mortality is high despite recent treatment breakthroughs and a greater understanding of its pathophysiology. Stress is one of the major causes of triggering different cellular signalling cascades inside the body and which might turn toward the development of cancer. Naturally occurring plant compounds or phytochemicals are being studied for medical purposes. Phytochemicals' benefits are being analyzed for inflammatory illnesses, liver failure, metabolic disorders, neurodegenerative disorders, and nephropathies. Cancer treatment with fewer side effects and better outcomes has been achieved by combining phytochemicals with chemotherapy. Resveratrol, curcumin, and epigallocatechin-3-gallate have been studied for their chemotherapeutic and chemopreventive potentiality, but hydrophobicity, solubility, poor bioavailability, and target selectivity limit the clinical uses of these compounds. The therapeutic potential is maximized by utilizing nanocarriers such as liposomes, micelles, nanoemulsions, and nanoparticles to increase phytochemical bioavailability and target specificity. This updated literature review discusses the clinical limitations, increased sensitivity, chemopreventive and chemotherapeutic effects, and the clinical limitations of the phytochemicals.

Synthesis and Investigation of Physicochemical and Biological Properties of Films Containing Encapsulated Propolis in Hyaluronic Matrix

The dynamic development of nanotechnology has enabled the development of innovative and novel techniques for the production and use of nanomaterials. One of them is the use of nanocapsules based on biodegradable biopolymer composites. Closing compounds with antimicrobial activity inside the nanocapsule cause the gradual release of biologically active substances into the environment, and the effect on pathogens is regular, prolonged and targeted. Known and used in medicine for years, propolis, thanks to the synergistic effect of active ingredients, has antimicrobial, anti-inflammatory and antiseptic properties. Biodegradable and flexible biofilms were obtained, the morphology of the composite was determined using scanning electron microscopy (SEM) and particle size was measured by the dynamic light scattering (DLS) method. Antimicrobial properties of biofoils were examined on commensal skin bacteria and pathogenic Candida isolates based on the growth inhibition zones. The research confirmed the presence of spherical nanocapsules with sizes in the nano/micrometric scale. The properties of the composites were characterized by infrared (IR) and ultraviolet (UV) spectroscopy. It has been proven that hyaluronic acid is a suitable matrix for the preparation of nanocapsules, as no significant interactions between hyaluronan and the tested compounds have been demonstrated. Color analysis and thermal properties, as well as the thickness and mechanical properties of the obtained films, were determined. Antimicrobial properties of the obtained nanocomposites were strong in relation to all analyzed bacterial and yeast strains isolated from various regions of the human body. These results suggest high potential applicability of the tested biofilms as effective materials for dressings to be applied on infected wounds.

Nanoliposome-Loaded Phenolics from Nasturtium officinale Improves Health Parameters in a Colorectal Cancer Mouse Model

Nasturtium officinale contains high amounts of phytochemical compounds that work against oxidative damages leading to improved health conditions in animals as well as humans. The study was performed to investigate the health benefits of nonencapsulated and nanoliposome-encapsulated phenolic rich fractions obtained from Nasturtium officinale on mice induced colorectal cancer. The experiment focused on encapsulation efficiency in improving the effectiveness of plant bioactive compounds. Phenolic rich fractions (PRF) were successfully loaded in the nanoliposome structure, a nanometer in size, of spherical shape and with homogeneous dispersion. Induction of colorectal cancer in mice impaired weight gain and feed intake, liver function and structural characteristics of ileum, while the dietary administration of nanoliposome-encapsulated PRF regulated the expression of Caspase 3, Bax, Bcl2, iNOS and SOD genes in the tumor tissue. The addition of nonencapsulated PRF and nanoliposome encapsulated PRF at the concentration of 100 mg TPC/kg BW/day improved the genes expression, although the nanoliposome-encapsulated PRF revealed better health outcomes compared to nonencapsulated PRF. Furthermore, both PRF improved intestinal morphology when the mice were challenged with colorectal cancer. The higher health promoting activity of nanoliposome-encapsulated PRF could be associated with its enhanced intestinal absorption, bioavailability, bioaccessibility and bioactivity. Consequently, the nanoliposome-encapsulated PRF could be considered as a promising anticancer agent against colorectal cancer.

Curcumin-PLGA based nanocapsule for the fluorescence spectroscopic detection of dopamine

The main purpose of this paper is to design curcumin loaded PLGA nanocapsules for the selective detection of dopamine using fluorescence spectroscopy. In the present work curcumin loaded PLGA nanocapsules were synthesized using a solid-in-oil-in water (s/o/w) emulsion technique. The prepared nanocapsules were coated with a poly(diallyldimethylammonium)chloride (PDDA) polymer to increase the entrapment of curcumin into the core of PLGA polymer. PLGA-Cur-PDDA nanocapsules were characterized using different microscopic and spectroscopic techniques. Unlike free curcumin, the formed CUR-PLGA-PDDA NCs were established as nanoprobes for the selective detection of dopamine molecules. The selectivity and specificity of nanocapsules toward dopamine was achieved by measuring the fluorescence emission spectra of the NCs in the presence of other interference molecules such as tryptophan, melamine, adenine, etc. It was noticed that increasing the concentration of the different molecules had no significant change in the fluorescence signal of the nanocapsules. These results confirm the strong quenching between dopamine and curcumin in the nanocapsules. Hence, this fluorescence emission technique was found to be selective, easy and fast with low cost for the determination of dopamine in a concentration range up to 5 mM with a detection limit equal to 22 nM.

A Unifying Perspective in Blunting the Limited Oral Bioavailability of Curcumin: A Succinct Look

BACKGROUND

Curcumin is a polyphenolic compound derived from rhizomes of Curcuma longa, the golden spice. Curcumin has drawn much attention in recent years of biomedical research owing to its wide variety of biologic and pharmacologic actions. It exerts antiproliferative, antifibrogenic, anti-inflammatory, and antioxidative effects, among various imperative pharmacologic actions. In spite of its well-documented efficacies against numerous disease conditions, the limited systemic bioavailability of curcumin is a continuing concern. Perhaps, the poor bioavailability of curcumin may have curtailed its significant development from kitchen to clinic as a potential therapeutic agent. Subsequently, there have been a considerable number of studies over decades researching the scientific basis of curcumin's reduced bioavailability and eventually improvement of its bioavailability employing a variety of therapeutic approaches, for instance, in combination with piperine, the bio-active constituent of black pepper. Piperine has remarkable potential to modulate the functional activity of metabolic enzymes and drug transporters, and thus there has been a great interest in the therapeutic application of this widely used spice as alternative medicine and bioavailability enhancer. Growing body of evidence supports the synergistic potential of curcumin against numerous pathologic conditions when administered with piperine.

CONCLUSION

In light of current challenges, the major concern pertaining to poor systemic bioavailability of curcumin, its improvement, especially in combination with piperine, and the necessity of additional research in this setting are together described in this review. Besides, the recent advances in the potential therapeutic rationale and efficacy of curcumin-piperine combination, a promising duo, against various pathologic conditions are delineated.

Curcumin can improve Parkinson's disease via activating BDNF/PI3k/Akt signaling pathways

Parkinson's disease is a common progressive neurodegenerative disease, and presently has no curative agent. Curcumin, as one of the natural polyphenols, has great potential in neurodegenerative diseases and other different pathological settings. The brain-derived neurotrophic factor (BDNF) and phosphatidylinositol 3 kinase (PI3k)/protein kinase B (Akt) signaling pathways are significantly involved nerve regeneration and anti-apoptotic activities. Currently, relevant studies have confirmed that curcumin has an optimistic impact on neuroprotection via regulating BDNF and PI3k/Akt signaling pathways in neurodegenerative disease. Here, we summarized the relationship between BDNF and PI3k/Akt signaling pathway, the main biological functions and neuroprotective effects of curcumin via activating BDNF and PI3k/Akt signaling pathways in Parkinson's disease. This paper illustrates that curcumin, as a neuroprotective agent, can delay the progression of Parkinson's disease by protecting nerve cells.

Curcumin and Derivatives in Nanoformulations with Therapeutic Potential on Colorectal Cancer

There is growing concern in the rise of colorectal cancer (CRC) cases globally, and with this rise is the presentation of drug resistance. Like other cancers, current treatment options are either invasive or manifest severe side effects. Thus, there is a move towards implementing safer treatment options. Curcumin (CUR), extracted from Curcuma longa, has received significant attention by scientists as possible alternative to chemotherapeutic agents. It is safe and effective against CRC and nontoxic in moderate concentrations. Crucially, it specifically modulates apoptotic effects on CRC. However, the use of CUR is limited by its low solubility and poor bioavailability in aqueous media. These limitations are surmountable through novel approaches, such as nanoencapsulation of CUR, which masks the physicochemical properties of CUR, thus potentiating its anti-CRC effects. Furthermore, chemical derivatization of CUR is another approach that can be used to address the above constraints. This review spans published work in the last two decades, with key findings employing either of the two approaches, in addition to a combined approach in managing CRC. The combined approach affords the possibility of better treatment outcomes but not widely investigated nor yet clinically implemented.

Mesoporous silica@chitosan@gold nanoparticles as "on/off" optical biosensor and pH-sensitive theranostic platform against cancer

A cancer nanotheranostic system was fabricated based on mesoporous silica@chitosan@gold (MCM@CS@Au) nanosystem targeted by aptamer toward the MUC-1 positive tumor cells. Subsequently, curcumin as an efficient herbal anticancer drug was first encapsulated into chitosan-triphosphate nanoparticles and then the resulted nanoparticle was loaded into the nanosystem (MCM@CS@Au-Apt). The nanosystem successful fabrication was approved at each synthesis step through FTIR, XRD, BET, DLS, FE-SEM, HRTEM, and fluorescence spectroscopy. Besides, the interaction between aptamer and curcumin was evaluated using full atomistic molecular dynamics simulations. The mechanism of curcumin release was likewise investigated through different kinetic models. Afterwards, the potential of the designed nanosystem in targeted imaging, and drug delivery was evaluated using fluorescence microscopy and flow cytometry. It was found that the energy transfer between the base pairs in the hairpin of double strands of DNA aptamer acts as a quencher for MCM@CS@Au fluorescence culminating in an "on/off" optical biosensor. On the other hand, the presence of pH-sensitive chitosan nanoparticles creates smart nanosystem to deliver more curcumin into the desired cells. Indeed, when the aptamer specifically binds to the MUC-1 receptor, its double strands separate under the low pH condition, leading to the drug release and the recovery of the fluorescence ("On" state). Based on the toxicity results, this nanosystem had more toxicity toward the MUC-1-positive tumor cells than MUC-1-negative cells, representing its selective targeting. Therefore, this nanosystem could be introduced as a smart anticancer nanotheranostic system for tracing particular biomarkers (MUC-1), non-invasive fluorescence imaging, and targeted curcumin delivery.

Crystal Structure, Solubility, and Pharmacokinetic Study on a Hesperetin Cocrystal with Piperine as Coformer

Hesperetin (HES) is a key biological active ingredient in citrus peels, and is one of the natural flavonoids that attract the attention of researchers due to its numerous therapeutic bioactivities that have been identified in vitro. As a bioenhancer, piperine (PIP) can effectively improve the absorption of insoluble drugs in vivo. In the present study, a cocrystal of HES and PIP was successfully obtained through solution crystallization. The single-crystal structure was illustrated and comprehensive characterization of the cocrystal was conducted. The cocrystal was formed by two drug molecules at a molar ratio of 1:1, which contained O–H–O hydrogen bonds between the carbonyl and ether oxygen of PIP and the phenolic hydroxyl group of HES. In addition, a solubility experiment was performed on powder cocrystal in simulated gastrointestinal fluid, and the result revealed that the cocrystal improves the dissolution behavior of HES compared with that of the pure substance. Furthermore, HES’s bioavailability in the cocrystal was six times higher than that of pristine drugs. These results may provide an efficient oral formulation for HES.

Curcumin-Induced Membrane Property Changes in DMPC Multilamellar Vesicles and the Effects of Membrane-Destabilizing Molecules on Curcumin-Loaded Multilamellar Vesicles

Curcumin (CUR) is the major bioactive component of turmeric (Curcuma longa), commonly used as a spice and traditional medicine in India. CUR possesses a wide range of pharmacological benefits, including antioxidant, anticarcinogenic, antimutagenic, anti-inflammatory, anti-Alzheimer, and anti-Parkinson effects. The CUR-membrane interaction is believed to be the reason for such biological activity of CUR. Several research groups have modeled the interaction of CUR with artificial model lipid membranes using various techniques such as nuclear magnetic resonance (NMR), small-angle X-ray scattering (SAXS), and differential scanning calorimetry (DSC). However, the mechanism of its action is still unclear. A fluorescent-probe-based technique could be advantageous to study the CUR-lipid membrane interaction due to its sensitivity toward the local environment and its multiparametric nature. In this work, we have used the intrinsic fluorescence properties of CUR to investigate CUR-induced physical property changes in 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) multilamellar vesicles (MLVs) at various CUR concentrations. By rationalizing the results of steady-state fluorescence intensity, fluorescence anisotropy, temperature-dependent fluorescence intensity, temperature-dependent fluorescence anisotropy, and quenching experiments, we have proposed a model showing concentration-dependent effects of CUR on the DMPC bilayer membrane. We suggest that at low concentrations (≤1 mol %), CUR is homogeneously distributed in the DMPC bilayer membrane in both the solid gel (SG) and liquid crystalline (LC) phases. At high concentrations (>1 mol %), CUR molecules form segregated domains that fluidize both membrane phases. However, the CUR-induced fluidization is less pronounced in the LC phase as some CUR molecules from the domain partition into the bilayer core. Further, the effects of membrane-destabilizing molecules such as bile salts, capsaicin (CAP), and piperine (PIP) on CUR-loaded DMPC multilamellar vesicles were studied. Our work also shows that CUR has a stabilizing effect on the DMPC membrane at high concentrations.

Accelerating charge transfer via nonconjugated polyelectrolyte interlayers toward efficient versatile photoredox catalysis

One of the challenges for high-efficiency single-component-based photoredox catalysts is the low charge transfer and extraction due to the high recombination rate. Here, we demonstrate a strategy to precisely control the charge separation and transport efficiency of the catalytic host by introducing electron or hole extraction interlayers to improve the catalytic efficiency. We use simple and easily available non-conjugated polyelectrolytes (NCPs) (i.e., polyethyleneimine, PEI; poly(allylamine hydrochloride), PAH) to form interlayers, wherein such NCPs consist of the nonconjugated backbone with charge transporting functional groups. Taking CdS as examples, it is shown that although PEI and PAH are insulators and therefore do not have the ability to conduct electricity, they can form good electron or hole transport extraction layers due to the higher charge-transfer kinetics of pendant groups along the backbones, thereby greatly improving the charge transfer capability of CdS. Consequently, the resultant PEI-/PAH-functionalized nanocomposites exhibit significantly enhanced and versatile photoredox catalysis.

Microparticles vs. Macroparticles as Curcumin Delivery Vehicles: Structural Studies and Cytotoxic Effect in Human Adenocarcinoma Cell Line (LoVo)

This study aimed to characterize the hydrogel micro- and macro-particles designed to deliver curcumin to human colon cancer cells (LoVo). Six series of vehicles based on sodium alginate (micro- and macro-particles, uncoated, coated with chitosan or gelatin) were synthesized. The uncoated microparticles were fabricated using an emulsion-based technique and the uncoated macroparticles with an extrusion technique, with both coupled with ionotropic gelation. The surface morphology of the particles was examined with scanning electron microscopy and the average size was measured. The encapsulation efficiency, moisture content, and swelling index were calculated. The release of curcumin from the particles was studied in an experiment simulating the conditions of the stomach, intestine, and colon. To evaluate the anticancer properties of such targeted drug delivery systems, the cytotoxicity of both curcumin-loaded and unloaded carriers to human colon cancer cells was assessed. The microparticles encapsulated much less of the payload than the macroparticles and released their content in a more prolonged manner. The unloaded carriers were not cytotoxic to LoVo cells, while the curcumin-loaded vehicles impaired their viability-more significantly after incubation with microparticles compared to macroparticles. Gelatin-coated or uncoated microparticles were the most promising carriers but their potential anticancer activity requires further thorough investigation.

Piperine: Chemical, biological and nanotechnological applications

Piperine (PIP) is an alkaloid present in several species of piper, mainly Piper nigrum Linn. and P. longum, among other species. The present article provides a comprehensive review of PIP research in the last years concerning its chemical properties, synthesis, absorption, metabolism, bioavailability and toxicity. The reviewed PIP literature has shown many pharmacological properties, such as antidiabetic, antidiarrheal, antioxidant, antibacterial, and anti-parasitic activity of PIP. However, its low solubility and absorption make its application challenging. This review also includes advances in the development of nanosystems containing PIP, including liposomes, micelles, metal nanoparticles, nanofibers, polymeric nanoparticles, and solid-lipid nanoparticles. Finally, we discuss different in vitro and in vivo studies to evaluate the biological activity of this drug, as well as some methods for the synthesis of nanosystems and their physical characteristics.

Novel γ-cyclodextrin-metal-organic frameworks for encapsulation of curcumin with improved loading capacity, physicochemical stability and controlled release properties

A safe and biodegradable γ-cyclodextrin-metal-organic-frameworks (γ-CD-MOFs) was successfully synthesized by using an improved hydrothermal method. In this study, curcumin (Cur) was chosen for testing the encapsulation stability and release performance of γ-CD-MOFs. Results of the crystal structure measurement indicated that the encapsulated curcumin within γ-CD-MOFs via van der Waals forces, hydrophobic interactions and hydrogen bonding was failed to disturb the inherent microtopography and crystallinity of γ-CD-MOFs. Compared to individual γ-CD, the γ-CD-MOFs exhibited improved loading capacity, physicochemical stability as well as controlled-release property in simulated digestion, and hence can be regarded as effective carriers for curcumin. Curcumin-loaded γ-CD-MOFs with a Cur : γ-CD-MOFs mass ratio of 2:3 (Cur-CD-MOFs/3), which showed the highest encapsulation efficiency (67.31 ± 2.25%), improved physicochemical stability and controlled-release performance, was selected for further research and industrialization. Our results demonstrate that γ-CD-MOFs can be regarded as a promising novel carrier for the delivery of curcumin or other hydrophobic nutraceuticals.

Preparation, Characterization and Antioxidant Activities of Kelp Phlorotannin Nanoparticles

Phlorotannins are a group of major polyphenol secondary metabolites found only in brown algae and are known for their bioactivities and multiple health benefits. However, they can be oxidized due to external factors and their bioavailability is low due to their low water solubility. In this study, the potential of utilizing nanoencapsulation with polyvinylpyrrolidone (PVP) to improve various activities of phlorotannins was explored. Phlorotannins encapsulated by PVP nanoparticles (PPNPS) with different loading ratios were prepared for characterization. Then, the PPNPS were evaluated for in vitro controlled release of phlorotannin, toxicity and antioxidant activities at the ratio of phlorotannin to PVP 1:8. The results indicated that the PPNPS showed a slow and sustained kinetic release of phlorotannin in simulated gastrointestinal fluids, they were non-toxic to HaCaT keratinocytes and they could reduce the generation of endogenous reactive oxygen species (ROS). Therefore, PPNPS have the potential to be a useful platform for the utilization of phlorotannin in both pharmaceutical and cosmetics industries.

Comparison of Emulsion and Nanoemulsion Delivery Systems: The Chemical Stability of Curcumin Decreases as Oil Droplet Size Decreases

The water dispersibility, chemical stability, and bioaccessibility of curcumin, a labile hydrophobic nutraceutical, can be enhanced by incorporating it inside the oil droplets of oil-in-water emulsions or nanoemulsions. In these multiphase systems, the curcumin remains relatively stable to degradation when surrounded by oil but degrades rapidly when surrounded by water. We hypothesized that the size of the lipid droplets would therefore impact the stability of encapsulated curcumin by altering the surface area of oil exposed to water. The effect of droplet surface area on the kinetics of curcumin degradation was therefore studied by producing emulsions with different mean droplet diameters (d₃₂) and therefore different specific surface areas (A_S): large (d₃₂ = 20.9 μm; A_S = 300 m² kg^-1); medium (d₃₂ = 2.53 μm; A_S = 2500 m² kg^-1); small (d₃₂ = 0.26 μm; A_S = 24,000 m² kg^-1); and very small (d₃₂ = 0.083 μm; A_S = 80,000 m² kg^-1) emulsions. All the emulsions initially had milky-yellow appearances and were relatively stable to aggregation during the course of the experiments. However, rapid creaming was observed in the large and medium emulsions because of their relatively large droplet size. The emulsions all exhibited some color fading during storage, with the rate of curcumin degradation increasing with decreasing droplet size. For instance, the percentage of curcumin remaining in the emulsions after 17 days storage was 91.4 ± 1.5 > 77.3 ± 6.6 > 66.7 ± 1.9 ≫ 30.6 ± 2.8% for the large, medium, small, and very small emulsions, respectively. The more rapid chemical degradation of the curcumin in the smaller droplets can be attributed to the fact that curcumin exchange between the interior and exterior of the droplets occurs more rapidly as the droplet dimensions decrease. Our results indicate that the droplet size plays a critical role in the degradation of curcumin encapsulated in emulsions, which may have important consequences for the formulation of curcumin-enriched foods and beverages with enhanced bioactivity. In particular, it suggests that emulsions are more effective at chemically stabilizing curcumin than nanoemulsions.

Efficacy of Polymer-Based Nanocarriers for Co-Delivery of Curcumin and Selected Anticancer Drugs

Cancer remains a heavy health burden resulting in a high rate of mortality around the world. The presently used anticancer drugs suffer from several shortcomings, such as drug toxicity, poor biodegradability and bioavailability, and poor water solubility and drug resistance. Cancer is treated effectively by combination therapy whereby two or more anticancer drugs are employed. Most of the combination chemotherapies result in a synergistic effect and overcome drug resistance. Furthermore, the design of polymer-based nanocarriers for combination therapy has been reported by several researchers to result in promising therapeutic outcomes in cancer treatment. Curcumin exhibits good anticancer activity but its poor bioavailability has resulted in its incorporation into several polymer-based nanocarriers resulting in good biological outcomes. Furthermore, the incorporation of curcumin together with other anticancer drugs have been reported to result in excellent therapeutic outcomes in vivo and in vitro. Due to the potential of polymer-based nanocarriers, this review article will be focused on the design of polymer-based nanocarriers loaded with curcumin together with other anticancer drugs.

Curcumin encapsulated colloidal amphiphilic block co-polymeric nanocapsules: colloidal nanocapsules enhance photodynamic and anticancer activities of curcumin

Curcumin-based novel colloidal nanocapsules were prepared from amphiphilic poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (F108). These colloidal nanocapsules appeared as spherical particles with size ranging between 270 and 310 nm. Curcumin fluorescence spectra exhibited an aggregation-induced 23 nm red-shift of the emission maximum in addition to the enhancement of the fluorescence quantum yield in these nanocapsules. The cytotoxicity of curcumin and colloidal nanocapsules was assessed using human derived immortalized cell lines (A549 and A375 cells) in the presence and absence of light irradiation. The nanocapsules exhibited a >30-fold decrease in IC₅₀, suggesting enhanced anticancer activity associated with curcumin encapsulation. Higher toxicity was also reported in the presence of light irradiation (as shown by the IC₅₀ data), indicating their potential for future application in photodynamic therapy. Finally, A375 cells treated with curcumin and the nanocapsules showed a significant increase in single- and/or double-strand DNA breaks upon exposure to light, indicating promising biological effects.

pH-Triggered Drug Release Controlled by Poly(Styrene Sulfonate) Growth Hollow Mesoporous Silica Nanoparticles

In the current report, hollow mesoporous silica (HMS) nanoparticles were successfully prepared by means of a hard-templating method and further modified with poly(styrene sulfonate) (PSS) via radical polymerization. Structural analysis, surface spectroscopy, and thermogravimetric characterization confirmed a successful surface modification of HMS nanoparticles. A hairy PSS was clearly visualized by high-resolution transmission electron microscopy measurement, and it is grown on the surface of HMS nanoparticles. The Brunauer-Emmett-Teller surface area and average pore size of HMS nanoparticles were reduced after surface modification because of the pore-blocking effect, which indicated that the PSS lies on the surface of nanoparticles. Nevertheless, the PSS acts as a "nano-gate" to control the release of curcumin which is triggered by pH. The drug-release profile of unmodified HMS nanoparticles showed a stormed release in both pH 7.4 and 5.0 of phosphate buffer saline buffer solution. However, a slow release (9.92% of cumulative release) of curcumin was observed at pH 7.4 when the surface of HMS nanoparticles was modified by PSS. The kinetic release study showed that the curcumin release mechanism from PSS@HMS nanoparticles followed the Ritger-Peppas kinetic model, which is the non-Fickian diffusion. Therefore, the PSS-decorated HMS nanoparticles demonstrate potential for pH-triggered drug release transport.

Understanding the intrinsic fluorescence of piperine in microheterogeneous media: partitioning and loading studies

Piperine, an ingredient of black pepper, is widely used in pharmaceutical applications.