Poloxamer 407/TPGS mixed micelles for delivery of gambogic acid to breast and multidrug-resistant cancer

Next-generation cancer nanotherapeutics: Pluronic® F127 based mixed micelles for enhanced drug delivery

Cancer, projected to become the second leading cause of mortality globally, underscores the critical need for precise drug delivery systems. Nanotechnology, particularly micelles, has emerged as a promising avenue. These nano-sized colloidal dispersions (< 100 nm) utilize amphiphilic molecules featuring a hydrophilic tail and hydrophobic core, facilitating efficient drug encapsulation and delivery. Pluronic® F127, a triblock copolymer (PEO101-PPO56-PEO101), has emerged as a promising drug carrier due to its non-ionic, less-toxic nature, which prolongs drug circulation time and improves drug delivery across blood-brain and intestinal barriers. Mixed micelles, formed using Pluronic® F127 combined with other polymers, surfactants, and drugs, enhance drug solubility, stability, and targeted delivery. This review highlights the key features of mixed micelles, including enhanced pharmacokinetics and targeting abilities, folic acid (FA) conjugation strategies, superior cytotoxicity with reduced side effects, overcoming multidrug resistance, and versatility across various cancer types and compounds. Additionally, the potential for clinical translation of Pluronic® F127-based mixed micelle in cancer treatment is discussed, addressing current challenges and paving the way for optimized applications.

Bioavailability enhancement of atazanavir sulphate using mixed micelles: in vitro characterization and in vivo pharmacokinetic study

This study aims to enhance the oral bioavailability of atazanavir sulphate, a human immunodeficiency virus-1 protease inhibitor known for its poor oral absorption, by formulating mixed micelles using Soluplus® and Kolliphor HS 15. Mixed micelles were prepared through the thin film hydration technique. The micelles were characterized for particle size, polydispersity index (PDI), zeta potential, entrapment efficiency, drug loading, and confirmed for atazanavir sulphate encapsulation via FTIR studies. In vitro release studies were conducted, and the morphology of the micelles was examined using TEM. Atazanavir sulphate mixed micelles exhibited a particle size of 62.92 nm, PDI of 0.221, zeta potential of - 17.8 mV, high entrapment efficiency (99.76 ± 1.06), and drug loading (14 ± 0.82). In vitro release studies demonstrated sustained release up to 12 h, with maximum solubility observed at 2 h under pH 1.2 conditions. TEM analysis revealed spherical micelle morphology. Oral administration of atazanavir sulphate mixed micelles showed a 1.23-fold increase in relative bioavailability compared to pure drug suspension. The formulation of mixed micelles using Soluplus® and Kolliphor HS 15 offers a promising strategy to improve the oral bioavailability of atazanavir sulphate. These findings suggest the potential utility of mixed micelles as an effective delivery system for atazanavir sulphate, offering enhanced therapeutic outcomes for patients.

Combination chemotherapy via poloxamer 188 surface-modified PLGA nanoparticles that traverse the blood-brain-barrier in a glioblastoma model

The effect of chemotherapy for anti-glioblastoma is limited due to insufficient drug delivery across the blood-brain-barrier. Poloxamer 188-coated nanoparticles can enhance the delivery of nanoparticles across the blood-brain-barrier. This study presents the design, preparation, and evaluation of a combination of PLGA nanoparticles (PLGA NPs) loaded with methotrexate (P-MTX NPs) and PLGA nanoparticles loaded with paclitaxel (P-PTX NPs), both of which were surface-modified with poloxamer188. Cranial tumors were induced by implanting C6 cells in a rat model and MRI demonstrated that the tumors were indistinguishable in the two rats with P-MTX NPs + P-PTX NPs treated groups. Brain PET scans exhibited a decreased brain-to-background ratio which could be attributed to the diminished metabolic tumor volume. The expression of Ki-67 as a poor prognosis factor, was significantly lower in P-MTX NPs + P-PTX NPs compared to the control. Furthermore, the biodistribution of PLGA NPs was determined by carbon quantum dots loaded into PLGA NPs (P-CQD NPs), and quantitative analysis of ex-vivo imaging of the dissected organs demonstrated that 17.2 ± 0.6% of the NPs were concentrated in the brain after 48 h. The findings highlight the efficacy of combination nanochemotherapy in glioblastoma treatment, indicating the need for further preclinical studies.

Injectable thermo-sensitive hydrogel enhances anti-tumor potency of engineered Lactococcus lactis by activating dendritic cells and effective memory T cells

Engineered bacteria have shown great potential in cancer immunotherapy by dynamically releasing therapeutic payloads and inducing sustained antitumor immune response with the crosstalk of immune cells. In previous studies, FOLactis was designed, which could secret an encoded fusion protein of Fms-related tyrosine kinase 3 ligand and co-stimulator OX40 ligand, leading to remarkable tumor suppression and exerting an abscopal effect by intratumoral injection. However, it is difficult for intratumoral administration of FOLactis in solid tumors with firm texture or high internal pressure. For patients without lesions such as abdominal metastatic tumors and orthotopic gastric tumors, intratumoral injection is not feasible and peritumoral maybe a better choice. Herein, an engineered bacteria delivery system is constructed based on in situ temperature-sensitive poloxamer 407 hydrogels. Peritumoral injection of FOLactis/P407 results in a 5-fold increase in the proportion of activated DC cells and a more than 2-fold increase in the proportion of effective memory T cells (TEM), playing the role of artificial lymph island. Besides, administration of FOLactis/P407 significantly inhibits the growth of abdominal metastatic tumors and orthotopic gastric tumors, resulting in an extended survival time. Therefore, these findings demonstrate the delivery approach of engineered bacteria based on in situ hydrogel will promote the efficacy and universality of therapeutics.

Phyto-cosmeceutical gel containing curcumin and quercetin loaded mixed micelles for improved anti-oxidant and photoprotective activity

Ultra Violet radiations induced skin damage and associated skin disorders are a widespread concern. The consequences of sun exposure include a plethora of dermal conditions like aging, solar urticaria, albinism and cancer. Sunscreens provide effective protection to skin from these damages. Besides FDA approved physical and chemical UV filters, phytoconstituents with their multi functionalities are emerging as frontrunners in Therapy of skin disorders. Objective of this study was to develop novel phyto-dermal gel (PDG) with dual action of sun protection and antioxidant potential using polymeric mixed micelles (PMMs) are nanocarriers. PMMs of Pluronic F127 and Pluronic F68 loaded with curcumin and quercetin were optimized by 32 factorial designs. Responses studied were vesicle size, SPF, entrapment efficiency of curcumin and quercetin and antioxidant activity. Droplet size ranged from 300 to 500 nm with PDI in between 0.248 and 0.584. Combination of curcumin and quercetin showed enhanced sun protection and antioxidant activity. Pluronics played a significant positive role in various parameters. In present studies vesicle size of factorial batches was found to be between 387 and 527 nm, and SPF was found to be between 18.86 and 28.32. Transmission electron microscopy revealed spherical morphology of micelles. Optimized micelles were incorporated into Carbopol 940. Optimized PDG was evaluated for pH, drug content, spreadability, rheology, syneresis, ex vivo permeation, and skin retention. Hysteresis loop in the rheogram suggested thixotropy of PDG. Syneresis for gels from day 0-30 days was found to be between 0% and 12.46% w/w. SPF of optimized PDG was 27±0.5. Optimized PDG showed no signs of erythema and edema on Wistar rats. PMMs thus effectively enhanced antioxidant and skin protective effect of curcumin and quercetin.

An approach for an enhanced anticancer activity of ferulic acid-loaded polymeric micelles via MicroRNA-221 mediated activation of TP53INP1 in caco-2 cell line

Ferulic acid (FA) has powerful antioxidant and antitumor activities, but it has low bioavailability owing to its poor water solubility. Our aim is to formulate polymeric mixed micelles loaded with FA to overcome its poor solubility and investigate its potential anticancer activity via miRNA-221/TP53INP1 axis-mediated autophagy in colon cancer. A D-optimal design with three factors was used for the optimization of polymeric mixed micelles by studying the effects of each of total Pluronics mixture (mg), Pluronic P123 percentage (%w/w), and drug amount (mg) on both entrapment efficiency (EE%) and particle size. The anticancer activity of FA and Tocopheryl polyethylene glycol 1000 succinate (TPGS) mixed micelles formula (O2) was assessed by MTT and flow cytometry. O2 showed an EE% of 99.89%, a particle size of 13.86 nm, and a zeta potential of - 6.02 mv. In-vitro drug release studies showed a notable increase in the release rate of FA from O2, as compared to the free FA. The (IC50) values for FA from O2 and free FA were calculated against different cell lines showing a prominent IC50 against Caco-2 (17.1 µg/ml, 191 µg/ml respectively). Flow cytometry showed that FA caused cell cycle arrest at the G2/M phase in Caco-2. RT-PCR showed that O2 significantly increased the mRNA expression level of Bax and CASP-3 (4.72 ± 0.17, 3.67 ± 0.14), respectively when compared to free FA (2.59 ± 0.13, 2.14 ± 0.15), while miRNA 221 levels were decreased by the treatment with O2 (0.58 ± 0.02) when compared to free FA treatment (0.79 ± 0.03). The gene expression of TP53INP1 was increased by the treatment with O2 compared to FA at P < 0.0001. FA-loaded TPGS mixed micelles showed promising results for enhancing the anticancer effect of FA against colorectal cancer, probably due to its enhanced solubility. Thus, FA-loaded TPGS mixed micelles could be a potential therapeutic agent for colorectal cancer by targeting miRNA-221/TP53INP1 axis-mediated autophagy.

Caged Polyprenylated Xanthones in Garcinia hanburyi and the Biological Activities of Them

The previous phytochemical analyses of Garcinia hanburyi revealed that the main structural characteristic associated with its biological activity is the caged polyprenylated xanthones with a unique 4-oxatricyclo [4.3.1.03,7] dec-2-one scaffold, which contains a highly substituted tetrahydrofuran ring with three quaternary carbons. Based on the progress in research of the chemical constituents, pharmacological effects and modification methods of the caged polyprenylated xanthones, this paper presents a preliminary predictive analysis of their drug-like properties based on the absorption, distribution, metabolism, excretion and toxicity (ADME/T) properties. It was found out that these compounds have very similar pharmacokinetic properties because they possess the same caged xanthone structure, the 9,10-double bond in a,b-unsaturated ketones are critical for the antitumor activity. The author believes that there is an urgent need to seek new breakthroughs in the study of these caged polyprenylated xanthones. Thus, the research on the route of administration, therapeutic effect, structural modification and development of such active ingredients is of great interest. It is hoped that this paper will provide ideas for researchers to develop and utilize the active ingredients derived from natural products.

Anti-proliferation and induction of mitochondria-mediated apoptosis by Garcinia hanburyi resin in colorectal cancer cells

Introduction

Several parts of Garcinia hanburyi are used in traditional medicine for many purposes. In this study, Garcinia hanburyi resin (GHR) was explored for possible anti-proliferative effects and the underlying mechanism on colorectal cancer (CRC) cells.

Methods

Gambogic acid (GA) content in GHR was analyzed by HPLC method. The cytotoxicities of GA and GHR were assessed in human CRC cell lines (SW480 and Caco-2) and normal colon cells (CCD841 CoN) using a trypan blue exclusion assay, MTS assay, and cell morphology analysis. Cell cycle and apoptosis at its half maximal inhibitory concentration (IC50) were analyzed using flow cytometry. And, the levels of intrinsic apoptosis-related proteins were measured by Western blot analysis.

Results

GA was the major compound as 71.26% of the GHR. The cell viability of CRC cells was decreased in a time- and dose-dependent manner after exposure to GHR. The selectivity index indicated that GHR had a high degree of selectivity against CRC cells. The same result was obtained for GA treatment. In addition, GHR markedly induced typical apoptotic morphology of CRC cells, but had no obvious effect on normal colon cells. GHR induced apoptosis with the cell cycle arrest at the G2/M phase. An increase in Bax/Bcl-2 ratio and a decrease in procaspase-3 proteins indicated that GHR promoted apoptosis by disrupting the mitochondrial outer membrane permeability and the subsequent activation of caspase-3.

Conclusion

GHR, which contained GA as an active compound, significantly inhibited CRC cell proliferation via the induction of intrinsic apoptosis, while having low toxicity on normal colon cells. Therefore, GHR could be proposed as a potent candidate for the treatment of CRC.

Pterostilbene-Loaded Soluplus/Poloxamer 188 Mixed Micelles for Protection against Acetaminophen-Induced Acute Liver Injury

Excessive acetaminophen (APAP) induces excess reactive oxygen species (ROS), leading to liver damage. Pterostilbene (PTE) has excellent antioxidant and anti-inflammatory activities, but poor solubility limits its biological activity. In this study, we prepared PTE-loaded Soluplus/poloxamer 188 mixed micelles (PTE-MMs), and the protective mechanism against APAP-induced liver injury was investigated. In vitro results showed that PTE-MMs protected H₂O₂-induced HepG2 cell proliferation inhibition, ROS accumulation, and mitochondrial membrane potential destruction. Immunofluorescence results indicated that PTE-MMs significantly inhibited H₂O₂-induced DNA damage and cGAS-STING pathway activation. For in vivo protection studies, PTE-MMs (25 and 50 mg/kg) were administered orally for 5 days, followed by APAP (300 mg/kg). The results showed that APAP significantly induced injury in liver histopathology as well as an increase in serum aspartate aminotransferase and alanine aminotransferase levels. Moreover, the above characteristics of APAP-induced acute liver injury were inhibited by PTE-MMs. In addition, APAP-induced changes in the activities of antioxidant enzymes such as SOD and GSH in liver tissue were also inhibited by PTE-MMs. Immunohistochemical results showed that PTE-MMs inhibited APAP-induced DNA damage and cGAS-STING pathway activation in liver tissues. For in vivo therapeutic effect study, mice were first given APAP (300 mg/kg), followed by oral administration of PTE-MMs (50 mg/kg) for 3 days. The results showed that PTE-MMs exhibited promising therapeutic effects on APAP-induced acute liver injury. In conclusion, our study shows that the Soluplus/poloxamer 188 MM system has the potential to enhance the biological activity of PTE in the protection and therapeutic of liver injury.

Surfactant and Block Copolymer Nanostructures: From Design and Development to Nanomedicine Preclinical Studies

The medical application of nanotechnology in the field of drug delivery has so far exhibited many efforts in treating simple to extremely complicated and life-threatening human conditions, with multiple products already existing in the market. A plethora of innovative drug delivery carriers, using polymers, surfactants and the combination of the above, have been developed and tested pre-clinically, offering great advantages in terms of targeted drug delivery, low toxicity and immune system activation, cellular biomimicry and enhanced pharmacokinetic properties. Furthermore, such artificial systems can be tailor-made with respect to each therapeutic protocol and disease type falling under the scope of personalized medicine. The simultaneous delivery of multiple therapeutic entities of different nature, such as genes and drugs, can be achieved, while novel technologies can offer systems with multiple modalities often combining therapy with diagnosis. In this review, we present prominent, innovative and state-of-the-art scientific efforts on the applications of surfactant-based, polymer-based, and mixed surfactant-polymer nanoparticle drug formulations intended for use in the medical field and in drug delivery. The materials used, formulation steps, nature, properties, physicochemical characteristics, characterization techniques and pharmacokinetic behavior of those systems, are presented extensively in the length of this work. The material presented is focused on research projects that are currently in the developmental, pre-clinical stage.

Nanosuspension: A Formulation Technology for Tackling the Poor Aqueous Solubility and Bioavailability of Poorly Soluble Drugs

The poor water solubility of numerous novel drug candidates presents significant challenges, particularly in terms of oral administration. This limitation can result in various undesirable clinical implications, such as inter-patient variability, poor bioavailability, difficulties in achieving a safe therapeutic index, increased costs, and potential risks of toxicity or inefficacy. Biopharmaceutics Classification System (BCS) class II drugs face particular hurdles due to their limited solubility in the aqueous media of the gastrointestinal tract. In such cases, parenteral administration is often employed as an alternative strategy. To address these challenges, nanosuspension techniques offer a promising solution for enhancing drug solubility and overcoming oral delivery obstacles. This technique has the potential to bridge the gap between drug discovery and preclinical use by resolving problematic solubility. This literature review has delved into contemporary nanosuspension preparation technologies and the incorporation of stabilizing ingredients within the formulation. Furthermore, the manuscript explores nanosuspension strategies for both oral and parenteral/other delivery routes, and separate discussions have been presented to establish a suitable flow that addresses the challenges and strategies relevant to each administration method.

Design, Fabrication and Evaluation of Stabilized Polymeric mixed micelles for Effective Management in Cancer Therapy

PURPOSE

Cancer is one of the most common and fatal disease, chemotherapy is the major treatment against many cancer types. The anti-apoptotic BCL-2 protein's expression was increased in many cancer types and Venetoclax (VLX; BCL-2 inhibitor) is a small molecule, which selectively inhibits this specified protein. In order to increase the clinical performance of this promising inhibitor as a repurposed drug, polymeric mixed micelles formulations approach was explored.

METHODS

The Venetoclax loaded polymeric mixed micelles (VPMM) were prepared by using Pluronic® F-127 and alpha tocopherol polyethylene glycol 1000 succinate (TPGS) as excipients by thin film hydration method and characteristics. The percentage drug loading capacity, entrapment efficiency and in-vitro drug release studies were performed using HPLC method. The cytotoxicity assay, cell uptake and anticancer activities were evaluated in two different cancer cells i.e. MCF-7 (breast cancer) and A-549 (lung cancer).

RESULTS

Particle size, polydispersity index and zeta potential of the VPMM was found to be 72.88 ± 0.09 nm, 0.078 ± 0.009 and -4.29 ± 0.24 mV, respectively. The entrapment efficiency and %drug loading were found to be 80.12 ± 0.23% and 2.13% ± 0.14%, respectively. The IC₅₀ of VLX was found to be 4.78, 1.30, 0.94 µg/ml at 24, 48 and 72 h, respectively in MCF-7 cells and 1.24, 0.68, and 0.314 µg/ml at 24, 48, and 72 h, respectively in A549 cells. Whereas, IC₅₀ of VPMM was found to be 0.42, 0.29, 0.09 µg/ml at 24, 48 and 72 h, respectively in MCF-7 cells and 0.85, 0.13, 0.008 µg/ml at 24, 48 and 72 h in A549 cells, respectively, indicating VPMM showing better anti-cancer activity compared to VLX. The VPMM showed better cytotoxicity which was further proven by other assays and explained the anti-cancer activity is shown through the generation of ROS, nuclear damage,apoptotic cell death and expression of caspase-3,7, and 9 activities in apoptotic cells.

CONCLUSION

The current investigation revealed that the Venetoclax loaded polymeric mixed micelles (VPMM) revealed the enhanced therapeutic efficacy against breast and lung cancer in vitro models.

Application of Nanomicelles in Enhancing Bioavailability and Biological Efficacy of Bioactive Nutrients

Nutraceuticals provide many biological benefits besides their basic nutritional value. However, their biological efficacies are often limited by poor absorption and low bioavailability. Nanomaterials have received much attention as potential delivery systems of nutrients and phytonutrients for multiple applications. Nanomicelles are nanosized colloidal structures with a hydrophobic core and hydrophilic shell. Due to their unique characteristics, they have shown great perspectives in food and nutraceutical science. In this review, we discussed the unique properties of nanomicelles. We also emphasized the latest advances on the design of different nanomicelles for efficient delivery and improved bioavailability of various nutrients. The role of nanomicelles in the efficacy improvement of bioactive components from nutraceutical and health foods has been included. Importantly, the safety concerns on nano-processed food products were highlighted.

Mixed Polymeric Micelles for Rapamycin Skin Delivery

Facial angiofibromas (FA) are one of the most obvious cutaneous manifestations of tuberous sclerosis complex. Topical rapamycin for angiofibromas has been reported as a promising treatment. Several types of vehicles have been used hitherto, but polymeric micelles and especially those made of d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) seem to have shown better skin bioavailability of rapamycin than the so far commonly used ointments. To better understand the influence of polymeric micelles on the behavior of rapamycin, we explored it through mixed polymeric micelles combining TPGS and poloxamer, evaluating stability and skin bioavailability to define an optimized formulation to effectively treat FA. Our studies have shown that TPGS improves the physicochemical behavior of rapamycin, i.e., its solubility and stability, due to a strong inclusion in micelles, while poloxamer P123 has a more significant influence on skin bioavailability. Accordingly, we formulated mixed-micelle hydrogels containing 0.1% rapamycin, and the optimized formulation was found to be stable for up to 3 months at 2–8 °C. In addition, compared to hydroalcoholic gel formulations, the studied system allows for better biodistribution on human skin.

Pharmaceutical Formulations with P-Glycoprotein Inhibitory Effect as Promising Approaches for Enhancing Oral Drug Absorption and Bioavailability

P-glycoprotein (P-gp) is crucial in the active transport of various substrates with diverse structures out of cells, resulting in poor intestinal permeation and limited bioavailability following oral administration. P-gp inhibitors, including small molecule drugs, natural constituents, and pharmaceutically inert excipients, have been exploited to overcome P-gp efflux and enhance the oral absorption and bioavailability of many P-gp substrates. The co-administration of small molecule P-gp inhibitors with P-gp substrates can result in drug–drug interactions and increased side effects due to the pharmacological activity of these molecules. On the other hand, pharmaceutically inert excipients, including polymers, surfactants, and lipid-based excipients, are safe, pharmaceutically acceptable, and are not absorbed from the gut. Notably, they can be incorporated in pharmaceutical formulations to enhance drug solubility, absorption, and bioavailability due to the formulation itself and the P-gp inhibitory effects of the excipients. Different formulations with inherent P-gp inhibitory activity have been developed. These include micelles, emulsions, liposomes, solid lipid nanoparticles, polymeric nanoparticles, microspheres, dendrimers, and solid dispersions. They can bypass P-gp by different mechanisms related to their properties. In this review, we briefly introduce P-gp and P-gp inhibitors, and we extensively summarize the current development of oral drug delivery systems that can bypass and inhibit P-gp to improve the oral absorption and bioavailability of P-gp substrates. Since many drugs are limited by P-gp-mediated efflux, this review is helpful for designing suitable formulations of P-gp substrates to enhance their oral absorption and bioavailability.

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.

Gambogic Acid as a Candidate for Cancer Therapy: A Review

Gambogic acid (GA), a kind of dry resin secreted by the Garcinia hanburyi tree, is a natural active ingredient with various biological activities, such as anti-cancer, anti-inflammatory, antioxidant, anti-bacterial effects, etc. An increasing amount of evidence indicates that GA has obvious anti-cancer effects via various molecular mechanisms, including the induction of apoptosis, autophagy, cell cycle arrest and the inhibition of invasion, metastasis, angiogenesis. In order to improve the efficacy in cancer treatment, nanometer drug delivery systems have been employed to load GA and form micelles, nanoparticles, nanofibers, and so on. In this review, we aim to offer a summary of chemical structure and properties, anti-cancer activities, drug delivery systems and combination therapy of GA, which might provide a reference to promote the development and clinical application of GA.

Berberine-Loaded Thiolated Pluronic F127 Polymeric Micelles for Improving Skin Permeation and Retention

Background

Challenges associated with local antibacterial and anti-inflammatory drugs include low penetration and retention of drugs at the expected action site. Additionally, improving these challenges allows for the prevention of side effects that are caused by drug absorption into the systemic circulation and helps to safely treat local skin diseases.

Methods

In the current study, we successfully prepared a thiolated pluronic F127 polymer micelles (BTFM), which binds to keratin through a disulphide bond, to produce skin retention. In addition, the small particle size of polymer micelles promotes the penetration of carriers into the skin. The current study was divided into two experiments: an in vitro experiment; an in vivo experiment that involved the penetration of the micelle-loaded drugs into the skin of rats, the skin irritation test and the anti-inflammatory activity of the drug-loaded micelles on dimethyl benzene-induced ear edema in mice.

Results

Results from our in vitro transdermal experiment revealed that the amount of drug absorbed through the skin was decreased after the drug was loaded in the BTFM. Further, results from the vivo study, which used fluorescence microscopy to identify the location of the BTFM after penetration, revealed that there was strong fluorescence in the epidermis layer, but there was no strong fluorescence in the deep skin layer. In addition, the BTFM had a very good safety profile with no potentially hazardous skin irritation and transdermal administration of BTFM could significantly suppress ear edema induced by dimethyl benzene. Therefore, these findings indicated that BTFM reduced the amount of drug that entered the systemic circulation. Our results also demonstrated that the BTFM had a certain affinity for keratin.

Conclusion

Our experimental results suggest that the BTFM may be an effective drug carrier for local skin therapy with good safety profile.

Innovative coenzyme Q10-loaded nanoformulation as an adjunct approach for the management of moderate periodontitis: preparation, evaluation, and clinical study

Periodontal diseases are worldwide chronic inflammatory conditions that are associated with heavy production of reactive oxygen species followed by damage of the tooth-supporting tissues. Although the mechanical approach of scaling and root planing (SRP) for removing of plaque is considered as the key element for controlling periodontitis, the anatomical complexity of the teeth hinders accessibility to deeper points. The aim of this study was to design a micellar nanocarrier of coenzyme Q10 (Q₁₀) to support the management of moderate periodontitis. Q₁₀ was formulated in nanomicelles (NM_Q10) and evaluated regarding encapsulation efficiency, loading efficiency, percent yield, hydrodynamic size (D_h), polydispersity index (PDI), and zeta potential (ζ potential). NM_Q10 was incorporated to in situ gelling systems and the in vitro release of Q₁₀ was studied. A clinical study including evaluation of periodontal parameters and biochemical assay of total antioxidant capacity (T-AOC) and lipid peroxide was achieved. Results revealed that Q₁₀ was efficiently entrapped in spherical-shaped stable NM_Q10 with D_h, PDI, and ζ potential of 154.0 nm, 0.108, and - 31.67 mV, respectively. The clinical study revealed that SRP only exhibited improvement of the periodontal parameters. Also, assay of T-AOC and lipid peroxide revealed that their values diminished by 21.5 and 23.8%, respectively. On the other hand, SRP combined with local application of NM_Q10 resulted in a significant management of the periodontal parameters, and likewise, the assayed biomarkers proved enhanced antioxidant activity over SRP alone. In conclusion, NM_Q10 can be suggested as a promising nanosystem as an approach to support the management of chronic periodontitis. Such results could be used to conduct larger clinical studies. Graphical abstrac.

Galactosylated TPGS Micelles for Docetaxel Targeting to Hepatic Carcinoma: Development, Characterization, and Biodistribution Study

Hepatocellular carcinoma (HCC) is a foremost type of cancer problem in which asialoglycoprotein receptors are overexpressed. In this study, asialoglycoprotein receptor-targeted nanoformulation (galactose-conjugated TPGS micelles) loaded with docetaxel (DTX) was developed to achieve its site-specific delivery for HCC therapy. The pharmaceutical characteristics like shape morphology, average particle size and zeta potential, drug entrapment efficiency, and in vitro release kinetics of developed system were evaluated. DTX-loaded galactosylated TPGS (DTX-TPGS-Gal) micelles and TPGS micelles (DTX-TPGS) were having 58.76 ± 1.82% and 54.76 ± 1.42% entrapment of the DTX, respectively. In vitro drug release behavior from micelles was controlled release. Cytotoxicitiy (IC₅₀) of DTX-TPGS-Gal formulation on HepG2 cell lines was significantly (p ≤ 0.01) lower (6.3 ± 0.86 μg/ml) than DTX-TPGS (9.06 ± 0.82 μg/ml) and plain DTX (16.06 ± 0.98 μg/ml) indicating higher efficacy of targeted formulation. Further, in vivo biodistribution studies in animal model showed maximum drug accumulation at target site, i.e., the liver in the case of DTX-TPGS-Gal as compared with non-targeted one. It is concluded from the findings that TPGS-Gal micelles can be utilized for targeted drug delivery of cytotoxic drugs towards HCC with minimized side effects. Graphical abstract.

Gambogic acid: A shining natural compound to nanomedicine for cancer therapeutics

The United States Food and Drug Administration has permitted number of therapeutic agents for cancer treatment. Most of them are expensive and have some degree of systemic toxicity which makes overbearing in clinical settings. Although advanced research continuously applied in cancer therapeutics, but drug resistance, metastasis, and recurrence remain unanswerable. These accounts to an urgent clinical need to discover natural compounds with precisely safe and highly efficient for the cancer prevention and cancer therapy. Gambogic acid (GA) is the principle bioactive and caged xanthone component, a brownish gamboge resin secreted from the of Garcinia hanburyi tree. This molecule showed a spectrum of biological and clinical benefits against various cancers. In this review, we document distinct biological characteristics of GA as a novel anti-cancer agent. This review also delineates specific molecular mechanism(s) of GA that are involved in anti-cancer, anti-metastasis, anti-angiogenesis, and chemo-/radiation sensitizer activities. Furthermore, recent evidence, development, and implementation of various nanoformulations of gambogic acid (nanomedicine) have been described.

Development of a Tumor-Responsive Nanopolyplex Targeting Pancreatic Cancer Cells and Stroma

Desmoplasia plays a pivotal role in promoting pancreatic cancer progression and is associated with poor clinical outcome. Targeting the desmoplastic tumor microenvironment in combination with chemotherapy is therefore a promising strategy for pancreatic cancer therapy. Here, we report a novel biodegradable copolymer to codeliver LY2109761 (a TGF-β receptor I/II inhibitor) and CPI-613 (a novel chemotherapy agent) to desmoplastic stroma and tumor cells, respectively, in the tumor microenvironment. Hydrophobic CPI-613 is conjugated to the hydrophilic copolymer via a newly designed MMP-2-responsive linker to form a trigger-responsive nanopolyplex. LY2109761 is hydrophobic and encapsulated into the hydrophobic core of the nanopolyplex. The resulting nanopolyplex is modified with a plectin-1-targeting peptide to enhance the accumulation of the nanopolyplex in pancreatic tumors. The nanopolyplex aims to normalize the stroma by blocking the interaction between tumor cells and pancreatic stellate cells to inhibit the activation of pancreatic stellate cells and subsequently reduce the dense extracellular matrix. Normalized stroma increases the penetration of the nanopolyplex into the tumor. The nanopolyplex shows enhanced accumulation in xenograft pancreatic tumors in a biodistribution study. Moreover, the targeted nanopolyplex markedly inhibits tumor growth in an orthotopic pancreatic cancer mouse model by dual-targeting tumor cells and stroma. Overall, the multifunctional nanopolyplex is a promising platform for pancreatic cancer therapy.

Synthesis of TPGS/Curcumin Nanoparticles by Thin-Film Hydration and Evaluation of Their Anti-Colon Cancer Efficacy In Vitro and In Vivo

Curcumin (CCM) has many potential uses in anticancer chemotherapy, but its low water solubility poses a major problem, preventing its translation into clinical use. TPGS is a water-soluble derivative of vitamin E that acts as a surfactant with the ability to form micellar nanoparticles in water. More importantly, TPGS acts as a potent antioxidant that can neutralize intracellular reactive oxygen species (ROS). In this study, we solubilized CCM with TPGS using thin-film rehydration to prepare aqueous formulations containing CCM at clinically relevant concentrations. We found that the minimal TPGS:CCM ratio for producing nanoparticles was 5:1 (w/w): at or above this ratio, stable nanoparticles formed with an average particle diameter of 12 nm. CCM was released from TPGS/CCM micelles in simulated colonic and gastric fluids. These TPGS/CCM nanoparticles were shown to decrease intracellular ROS levels and apoptosis and inhibited migration of HT-29 human colon cancer cells more potently than free CCM. Pharmacokinetic analysis showed TPGS/CCM to be more bioavailable than free CCM after oral administration to rats. Our results suggest that TPGS/CCM may increase therapeutic efficacy of CCM against colon cancer and merits further investigation in a clinical setting.

Formulation and evaluation of mixed polymeric micelles of quercetin for treatment of breast, ovarian, and multidrug resistant cancers

Background

Quercetin (QCT), a naturally occurring flavonoid has a wide array of pharmacological properties such as anticancer, antioxidant and anti-inflammatory activities. QCT has low solubility in water and poor bioavailability, which limited its use as a therapeutic molecule. Polymeric micelles (PMs) is a novel drug delivery system having characteristics like smaller particle size, higher drug loading, sustained drug release, high stability, increased cellular uptake and improved therapeutic potential. In the present study, we have formulated and characterized mixed PMs (MPMs) containing QCT for increasing its anticancer potential.

Methods

The MPMs were prepared by thin film hydration method, and their physicochemical properties were characterized. The in vitro anticancer activity of the MPMs were tested in breast (MCF-7 and MDA-MB-231, epithelial and metastatic cancer cell lines, respectively), and ovarian (SKOV-3 and NCI/ADR, epithelial and multi-drug resistant cell lines, respectively) cancer.

Results

The optimal MPM formulations were obtained from Pluronic polymers, P123 and P407 with molar ratio of 7:3 (A16); and P123, P407 and TPGS in the molar ratio of 7:2:1 (A22). The size of the particles before lyophilization (24.83±0.44 nm) and after lyophilisation (37.10±4.23 nm), drug loading (8.75±0.41%), and encapsulation efficiency (87.48±4.15%) for formulation A16 were determined. For formulation A22, the particle size before lyophilization, after lyophilization, drug loading and encapsulation efficiency were 26.37±2.19 nm, 45.88±13.80 nm, 9.01±0.11% and 90.07±1.09%, respectively. The MPMs exhibited sustained release of QCT compared to free QCT as demonstrated from in vitro release experiments. The solubility of QCT was markedly improved compared to pure QCT. The MPMs were highly stable in aqueous media as demonstrated by their low critical micelle concentration. The concentration which inhibited 50% growth (IC₅₀) values of both micellar preparations in all the cancer cell lines were significantly less compared to free QCT.

Conclusion

Both the MPMs containing QCT could be used for effective delivery to different type of cancer and may be considered for further development.

Recent Advances in the Application of Vitamin E TPGS for Drug Delivery

D-ɑ-tocopheryl polyethylene glycol succinate (Vitamin E TPGS or TPGS) has been approved by FDA as a safe adjuvant and widely used in drug delivery systems. The biological and physicochemical properties of TPGS provide multiple advantages for its applications in drug delivery like high biocompatibility, enhancement of drug solubility, improvement of drug permeation and selective antitumor activity. Notably, TPGS can inhibit the activity of ATP dependent P-glycoprotein and act as a potent excipient for overcoming multi-drug resistance (MDR) in tumor. In this review, we aim to discuss the recent advances of TPGS in drug delivery including TPGS based prodrugs, nitric oxide donor and polymers, and unmodified TPGS based formulations. These potential applications are focused on enhancing delivery efficiency as well as the therapeutic effect of agents, especially on overcoming MDR of tumors. It also demonstrates that the clinical translation of TPGS based nanomedicines is still faced with many challenges, which requires more detailed study on TPGS properties and based delivery system in the future.

Sodium cholate-enhanced polymeric micelle system for tumor-targeting delivery of paclitaxel

PURPOSE

Polymeric micelles are attractive nanocarriers for tumor-targeted delivery of paclitaxel (PTX). High antitumor efficacy and low toxicity require that PTX mainly accumulated in tumors with little drug exposure to normal tissues. However, many PTX-loaded micelle formulations suffer from low stability, fast drug release, and lack of tumor-targeting capability in the circulation. To overcome these challenges, we developed a micellar formulation that consists of sodium cholate (NaC) and monomethoxy poly (ethylene glycol)-block-poly (d,l-lactide) (mPEG-PDLLA).

METHODS

PTX-loaded NaC-mPEG-PDLLA micelles (PTX-CMs) and PTX-loaded mPEG-PDLLA micelles (PTX-Ms) were formulated, and their characteristics, particle size, surface morphology, release behavior in vitro, pharmacokinetics and in vivo biodistributions were researched. In vitro and in vivo tumor inhibition effects were systematically investigated. Furthermore, the hemolysis and acute toxicity of PTX-CMs were also evaluated.

RESULTS

The size of PTX-CMs was 53.61±0.75 nm and the ζ-potential was -19.73±0.68 mV. PTX was released much slower from PTX-CMs than PTX-Ms in vitro. Compared with PTX-Ms, the cellular uptake of PTX-CMs was significantly reduced in macrophages and significantly increased in human cancer cells, and therefore, PTX-CMs showed strong growth inhibitory effects on human cancer cells. In vivo, the plasma AUC0-t of PTX-CMs was 1.8-fold higher than that of PTX-Ms, and 5.2-fold higher than that of Taxol. The biodistribution study indicated that more PTX-CMs were accumulated in tumor than PTX-Ms and Taxol. Furthermore, the significant antitumor efficacy of PTX-CMs was observed in mice bearing BEL-7402 hepatocellular carcinoma and A549 lung carcinoma. Results from drug safety assessment studies including acute toxicity and hemolysis test revealed that the PTX-CMs were safe for in vivo applications.

CONCLUSION

These results strongly revealed that NaC-mPEG-PDLLA micelles can tumor-target delivery of PTX and enhance drug penetration in tumor, suggesting that NaC-mPEG-PDLLA micelles are promising nanocarrier systems for anticancer drugs delivery.

Lactobionic acid-conjugated TPGS nanoparticles for enhancing therapeutic efficacy of etoposide against hepatocellular carcinoma

Many effective anti-cancer drugs have limited use in hepatocellular carcinoma (HCC) therapy due to the drug resistance mechanisms in liver cells. In recent years, tumor-targeted drug delivery and the inhibition of drug-resistance-related mechanisms has become an integrated strategy for effectively combating chemo-resistant cancer. Herein, lactobionic acid-conjugated d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS-LA conjugate) has been developed as a potential asialoglycoprotein receptor (ASGPR)-targeted nanocarrier and an efficient inhibitor of P-glycoprotein (P-gp) to enhance etoposide (ETO) efficacy against HCC. The main properties of ETO-loaded TPGS-LA nanoparticles (NPs) were tested through in vitro and in vivo studies after being prepared using the nanoprecipitation method and characterized by dynamic light scattering (DLS). According to the results, smaller (∼141.43 nm), positively charged ETO-loaded TPGS-LA NPs were more suitable for providing efficient delivery to hepatoma cells by avoiding the clearance mechanisms. It was found that ETO-loaded TPGS-LA NPs were noticeably able to enhance the cytotoxicity of ETO in HepG2 cells. Besides this, markedly higher internalization by the ASGPR-overexpressed HepG2 cells and efficient accumulation at the tumor site in vivo were revealed in the TPGS-LA NP group. More importantly, animal studies confirmed that ETO-loaded TPGS-LA NPs achieved the highest therapeutic efficacy against HCC. Interestingly, ETO-loaded TPGS-LA NPs also exhibited a great inhibitory effect on P-gp compared to the ETO-loaded TPGS NPs. These results suggest that TPGS-LA NPs could be used as a potential ETO delivery system against HCC.

Redox-sensitive Pluronic F127-tocopherol micelles: synthesis, characterization, and cytotoxicity evaluation

Pluronic F127 (F127), an amphiphilic triblock copolymer, has been shown to have significant potential for drug delivery, as it is able to incorporate hydrophobic drugs and self-assemble into nanosize micelles. However, it suffers from dissociation upon dilution owing to the relatively high critical micelle concentration and lack of stimuli-responsive behavior. Here, we synthesized the α-tocopherol (TOC) modified F127 polymer (F127-SS-TOC) via a redox-sensitive disulfide bond between F127 and TOC, which formed stable micelles at relatively low critical micelle concentration and was sensitive to the intracellular redox environment. The particle size and zeta potential of the F127-SS-TOC micelles were 51.87±6.39 nm and -8.43±2.27 mV, respectively, and little changes in both particle size and zeta potential were observed within 7 days at room temperature. With 10 mM dithiothreitol stimulation, the F127-SS-TOC micelles rapidly dissociated followed by a significant change in size, which demonstrated a high reduction sensitivity of the micelles. In addition, the micelles showed a high hemocompatibility even at a high micelle concentration (1,000 μg/mL). Low cytotoxicity of the F127-SS-TOC micelles at concentrations ranging from 12.5 μg/mL to 200 μg/mL was also found on both Bel 7402 and L02 cells. Overall, our results demonstrated F127-SS-TOC micelles as a stable and safe aqueous formulation with a considerable potential for drug delivery.

Hurdles in selection process of nanodelivery systems for multidrug-resistant cancer

PURPOSE

Most of the nanomedicines for treatment of multidrug-resistant cancer do not reach Phase III trials and many are terminated or withdrawn or are in an indeterminate state since long without any study results being presented. Extensive perusal of nanomedicine development research revealed that one of the critical aspects influencing clinical outcomes and which requires diligent scrutiny is selection process of nanodelivery system.

METHODS

Research papers and articles published on development of nanodelivery systems for treatment of multidrug-resistant cancer were analyzed. Observations and conclusions noted by these researchers which might shed some light on poor clinical performance of nanocarriers were collated and summarized under observation section. Further research articles were studied to find possible solutions which may be applied to these particular problems for resolving them. The inferences of these findings were composed in Result section.

RESULT

Plausible solutions for the observed obstacles were noted as examples of novel formulations that can yield the following: better in vivo imaging, precise targeting and dosing of a specific site and specific cell type in a particular cancer, modulation of tumor surroundings, intonation of systemic effects and high reproducibility.

CONCLUSION

The angle of approach to the development of best nanosystem for a specific type of tumor needs to be spun around. Some of these changes can be brought about by individual scientists, some need to be established by collated efforts of scientists globally and some await advent of better technologies. Regardless of the stratagem, it can be said decisively that the schematics of development phase need rethinking.

Tumor neovasculature-targeted cationic PEGylated liposomes of gambogic acid for the treatment of triple-negative breast cancer

Gambogic acid (GA) is a naturally derived potent anticancer agent with extremely poor aqueous solubility. In the present study, positively charged PEGylated liposomal formulation of GA (GAL) was developed for parenteral delivery for the treatment of triple-negative breast cancer (TNBC). The GAL was formulated with a particle size of 107.3 ± 10.6 nm with +32 mV zeta potential. GAL showed very minimal release of GA over 24 h period confirming the non-leakiness and stability of liposomes. In vitro cytotoxicity assays showed similar cell killing with GA and GAL against MDA-MB-231 cells but significantly higher inhibition of HUVEC growth was observed with GAL. Furthermore, GAL significantly (p < 0.05) inhibited the MDA-MB-231 orthotopic xenograft tumor growth with >50% reduction of tumor volume and reduction in tumor weight by 1.7-fold and 2.2-fold when compared to GA and controls, respectively. Results of western blot analysis indicated that GAL significantly suppressed the expression of apoptotic markers, bcl2, cyclinD1, survivin and microvessel density marker-CD31 and increased the expression of p53 and Bax compared to GA and control. Collectively, these data provide further support for the potential applications of cationic GAL in its intravenous delivery and its significant role in inhibiting angiogenesis against TNBC.

Matrix metalloproteinases-2/9-sensitive peptide-conjugated polymer micelles for site-specific release of drugs and enhancing tumor accumulation: preparation and in vitro and in vivo evaluation

Since elevated expression of matrix metalloproteinase (MMP)-2 and MMP-9 is commonly observed in several malignant tumors, MMPs have been widely reported as key factors in the design of drug delivery systems. Several strategies have been proposed to develop MMPs-responsive nanoparticles to deliver chemotherapeutics to malignant solid tumors. A stimuli-responsive drug delivery system, which could be cleaved by MMPs, was proposed in this study. By inserting an MMP-2/9 cleavable oligopeptide GPVGLIGK-NH₂ (GK8) as spacer between α-tocopherol succinate (α-TOS) and methoxy-polyethylene glycol molecular weight (MW 2000 Da) activated by N-hydroxysuccinimide (mPEG2K-NHS), mPEG2K-GK8-α-TOS (TGK) was synthesized as the primary ingredient for MMP-2/9-sensitive micelles composed of d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) and TGK (n:n =40:60, TGK micelles). mPEG2K-α-TOS (T2K) was similarly synthesized as nonsensitive control. The TGK micelles showed better stability than nonsensitive micelles composed of TPGS and T2K (n:n =40:60, T2K micelles) owing to the inserted peptide. Fluorescence resonance energy transfer results indicated that TGK micelles could be successfully cleaved by MMP-2/9. Effective drug release was demonstrated in the presence of collagenase type IV, a mixture of MMP-2 and MMP-9. Compared with nonsensitive micelles, docetaxel (DTX)-loaded TGK micelles showed a fold higher cellular uptake in HT1080 cells. While the half-maximal inhibitory concentration (IC₅₀) of TGK and T2K micelles were similar (P>0.05) in MCF-7 cells (MMP-2/9 underexpression), the IC₅₀ values of the aforementioned micelles were 0.064±0.006 and 0.122±0.009 μg/mL, respectively, in HT1080 cells (MMP-2/9 overexpression). The MMP-2/9-sensitive micelles also demonstrated desired tumor targeting and accumulation ability in vivo. The results of in vivo antitumor effect evaluation indicate that TGK micelles are potent against solid tumors while maintaining minimum systemic toxicity compared with T2K micelles and DTX.

Absorptive interactions of concurrent oral administration of (+)-catechin and puerarin in rats and the underlying mechanisms

AIM

(+)-Catechin and puerarin are polyphenol and flavonoid, respectively, in green tea and foodstuffs. They exhibit potent antioxidant activity and are widely used for treating cardiocerebrovascular diseases. The aim of this work was to investigate the potential interactions between (+)-catechin and puerarin following concurrent oral administration in rats, and their absorption mechanisms in Caco-2 cell monolayers.

METHODS

Pharmacokinetic studies were conducted in male rats received (+)-catechin (140 mg/kg, po) and/or puerarin (200 mg/kg, po). The cell uptake and transport behavior in Caco-2 cell monolayers and the interactions of the two compounds were analyzed.

RESULTS

When (+)-catechin and puerarin were administered concurrently, the AUC0-12 h and Cmax values of puerarin were 2.48-fold and 3.91-fold, respectively, as large as those of puerarin alone; the AUC0-12 h and Cmax values of (+)-catechin were decreased to 57.62% and 77.55%, respectively, compared with those of (+)-catechin alone. In Caco-2 cell monolayers, (+)-catechin (300 and 600 μmol/L) significantly increased the cell uptake and transport of puerarin, whereas puerarin (300 and 600 μmol/L) significantly decreased the cellular uptake and transport of (+)-catechin. Furthermore, both cyclosporine A (P-glycoprotein inhibitor) and MK-571 (MRP-2 inhibitor) significantly increased the cellular uptake and transport of (+)-catechin and puerarin.

CONCLUSION

Concurrent oral administration of (+)-catechin and puerarin significantly increased the absolute oral bioavailability of puerarin, but decreasing that of (+)-catechin. The competitive efflux of (+)-catechin and puerarin by P-glycoprotein and MRP-2 might lead to this interaction during their absorption process in the small intestine.

Bypassing P-Glycoprotein Drug Efflux Mechanisms: Possible Applications in Pharmacoresistant Schizophrenia Therapy

The efficient noninvasive treatment of neurodegenerative disorders is often constrained by reduced permeation of therapeutic agents into the central nervous system (CNS). A vast majority of bioactive agents do not readily permeate into the brain tissue due to the existence of the blood-brain barrier (BBB) and the associated P-glycoprotein efflux transporter. The overexpression of the MDR1 P-glycoprotein has been related to the occurrence of multidrug resistance in CNS diseases. Various research outputs have focused on overcoming the P-glycoprotein drug efflux transporter, which mainly involve its inhibition or bypassing mechanisms. Studies into neurodegenerative disorders have shown that the P-glycoprotein efflux transporter plays a vital role in the progression of schizophrenia, with a noted increase in P-glycoprotein function among schizophrenic patients, thereby reducing therapeutic outcomes. In this review, we address the hypothesis that methods employed in overcoming P-glycoprotein in cancer and other disease states at the level of the BBB and intestine may be applied to schizophrenia drug delivery system design to improve clinical efficiency of drug therapies. In addition, the current review explores polymers and drug delivery systems capable of P-gp inhibition and modulation.

Polymeric drugs: Advances in the development of pharmacologically active polymers

Synthetic polymers play a critical role in pharmaceutical discovery and development. Current research and applications of pharmaceutical polymers are mainly focused on their functions as excipients and inert carriers of other pharmacologically active agents. This review article surveys recent advances in alternative pharmaceutical use of polymers as pharmacologically active agents known as polymeric drugs. Emphasis is placed on the benefits of polymeric drugs that are associated with their macromolecular character and their ability to explore biologically relevant multivalency processes. We discuss the main therapeutic uses of polymeric drugs as sequestrants, antimicrobials, antivirals, and anticancer and anti-inflammatory agents.

Novel piperine-loaded Tween-integrated monoolein cubosomes as brain-targeted oral nanomedicine in Alzheimer's disease: pharmaceutical, biological, and toxicological studies

Alzheimer's disease (AD) is one of the most patient devastating central nervous system diseases with no curative therapy. An effective oral therapy with brain-targeting potential is required that is hampered by blood-brain barrier. Piperine (PIP) is a natural alkaloid with memory enhancing potentials. Oral PIP delivery suffers from its hydrophobicity and first-pass metabolism. In this study, novel Tween-modified monoolein cubosomes (T-cubs) were elaborated as bioactive nanocarriers for brain-targeted oral delivery of PIP. Seven liquid crystalline nanoparticles (cubosomes) were prepared testing different bioactive surfactants (Tween 80, poloxamer, and Cremophor). Full in vitro characterization was carried out based on particle size, zeta potential, polydispersity index, entrapment efficiency, and in vitro release. Morphological examination and structure elucidation were performed using transmission and polarizing microscopes. Sporadic dementia of Alzheimer's type was induced in 42 male Wistar rats on which full behavioral and biochemical testing was conducted. Brain toxicity was assessed based on Caspase-3 assay for apoptosis and tumor necrosis factor-α for inflammation. Liver and kidney toxicity studies were conducted as well. Among others, T-cubs exhibited optimum particle size (167.00±10.49 nm), polydispersity index (0.18±0.01), and zeta potential (-34.60±0.47 mv) with high entrapment efficiency (86.67%±0.62%). Cubs could significantly sustain PIP in vitro release. In vivo studies revealed T-cubs potential to significantly enhance PIP cognitive effect and even restore cognitive function to the normal level. Superiority of T-cubs over others suggested brain-targeting effect of Tween. Toxicological studies contended safety of cubs on kidney, liver, and even brain. T-cubs exhibited potential anti-inflammatory and anti-apoptotic activity of loaded PIP, indicating potential to stop AD progression that was first suggested in this article. Novel oral nanoparticles elaborated possess promising in vitro and in vivo characteristics with high safety for effective chronic treatment of AD.

Recent research on bioactive xanthones from natural medicine: Garcinia hanburyi

Garcinia hanburyi, a tropical plant found in south Asia, has a special long history in the development of both medicine and art. This review mainly focuses on the pharmacy research of the bioactive compounds from the plant in recent years. Preparative and analysis separation methods were introduced. Moreover, the chemical structure of the isolated compounds was included. The studies of biological activities of the caged xanthones from the plant, including antitumor, anti-HIV-1, antibacterial, and neurotrophic activities, were reviewed in detail. Furthermore, the mechanisms of its antitumor activity were also reviewed. As mentioned above, some of the xanthones from G. hanburyi can be promising drug candidates, which is worth studying. However, we still need much evidence to prove their efficacy and safety. So, further research is critical for the future application of xanthones from G. hanburyi.

Adding vitamin E-TPGS to the formulation of Genexol-PM: specially mixed micelles improve drug-loading ability and cytotoxicity against multidrug-resistant tumors significantly

Genexol-PM, produced by Samyang Company (Korea) is an excellent preparation of paclitaxel (PTX) for clinical cancer treatment. However, it cannot resolve the issue of multidrug resistance (MDR)—a significant problem in the administration of PTX to cancer patients. To increase the efficacy of Genexol-PM against MDR tumors, a mixed micelle capable of serving as a vehicle for PTX was developed, and two substances were chosen as carrier materials: 1) Polyethylene glycol–polylactic acid (PEG-PLA), the original vehicle of Genexol-PM. 2) Vitamin E-TPGS, an inhibitor of P-glycoprotein (P-gp). P-gp has been proven to be the main cause of MDR. In vitro evaluation indicated that the mixed micelle was an ideal PTX delivery system for the treatment of MDR tumors; the mixed micelle also showed a significantly better drug-loading coefficient than Genexol-PM.

Preparation, in vitro and in vivo evaluation of polymeric nanoparticles based on hyaluronic acid-poly(butyl cyanoacrylate) and D-alpha-tocopheryl polyethylene glycol 1000 succinate for tumor-targeted delivery of morin hydrate

Herein, we describe the preparation of a targeted cellular delivery system for morin hydrate (MH), based on a low-molecular-weight hyaluronic acid-poly(butyl cyanoacrylate) (HA-PBCA) block copolymer. In order to enhance the therapeutic effect of MH, D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) was mixed with HA-PBCA during the preparation process. The MH-loaded HA-PBCA “plain” nanoparticle (MH-PNs) and HA-PBCA/TPGS “mixed” nanoparticles (MH-MNs) were concomitantly characterized in terms of loading efficiency, particle size, zeta potential, critical aggregation concentration, and morphology. The obtained MH-PNs and MH-MNs exhibited a spherical morphology with a negative zeta potential and a particle size less than 200 nm, favorable for drug targeting. Remarkably, the addition of TPGS resulted in about 1.6-fold increase in drug-loading. The in vitro cell viability experiment revealed that MH-MNs enhanced the cytotoxicity of MH in A549 cells compared with MH solution and MH-PNs. Furthermore, blank MNs containing TPGS exhibited selective cytotoxic effects against cancer cells without diminishing the viability of normal cells. In addition, the cellular uptake study indicated that MNs resulted in 2.28-fold higher cellular uptake than that of PNs, in A549 cells. The CD44 receptor competitive inhibition and the internalization pathway studies suggested that the internalization mechanism of the nanoparticles was mediated mainly by the CD44 receptors through a clathrin-dependent endocytic pathway. More importantly, MH-MNs exhibited a higher in vivo antitumor potency and induced more tumor cell apoptosis than did MH-PNs, following intravenous administration to S180 tumor-bearing mice. Overall, the results imply that the developed nanoparticles are promising vehicles for the targeted delivery of lipophilic anticancer drugs.

Optimization of dexamethasone mixed nanomicellar formulation

The purpose of this study was to develop a clear aqueous mixed nanomicellar formulation (MNF) of dexamethasone utilizing both D-α-tocopherol polyethylene glycol-1000 succinate (Vit E TPGS) and octoxynol-40 (Oc-40). In this study, Vit E TPGS and Oc-40 are independent variables. Formulations were prepared following solvent evaporation method. A three level full-factorial design was applied to optimize the formulation based on entrapment efficiency, size, and polydispersity index (PDI). A specific blend of Vit E TPGS and Oc-40 at a particular wt% ratio (4.5:2.0) produced excellent drug entrapment, loading, small mixed nanomicellar size and narrow PDI. Solubility of DEX in MNF is improved by ~6.3-fold relative to normal aqueous solubility. Critical micellar concentration (CMC) for blend of polymers (4.5:2.0) was found to be lower (0.012 wt%) than the individual polymers (Vit E TPGS (0.025 wt%) and Oc-40 (0.107 wt%)). No significant effect on mixed nanomicellar size and PDI with one-factor or multi-factor interactions was observed. Qualitative (1)H NMR studies confirmed absence of free drug in the outer aqueous MNF medium. MNF appeared to be highly stable. Cytotoxicity studies on rabbit primary corneal epithelial cells did not indicate any toxicity suggesting MNF of dexamethasone is safe and suitable for human topical ocular drops after further in vivo evaluations.

Single-walled carbon nanotube and graphene nanodelivery of gambogic acid increases its cytotoxicity in breast and pancreatic cancer cells

Graphene and single-walled carbon nanotubes were used to deliver the natural low-toxicity drug gambogic acid (GA) to breast and pancreatic cancer cells in vitro, and the effectiveness of this complex in suppressing cellular integrity was assessed. Cytotoxicity was assessed by measuring lactate dehydrogenase release, mitochondria dehydrogenase activity, mitochondrial membrane depolarization, DNA fragmentation, intracellular lipid content, and membrane permeability/caspase activity. The nanomaterials showed no toxicity at the concentrations used, and the antiproliferative effects of GA were significantly enhanced by nanodelivery. The results suggest that these complexes inhibit human breast and pancreatic cancer cells grown in vitro. This analysis represents a first step toward assessing their effectiveness in more complex, targeted, nanodelivery systems.

Enhanced brain delivery of lamotrigine with Pluronic(®) P123-based nanocarrier

BACKGROUND

P-glycoprotein (P-gp) mediated drug efflux across the blood-brain barrier (BBB) is an important mechanism underlying poor brain penetration of certain antiepileptic drugs (AEDs). Nanomaterials, as drug carriers, can overcome P-gp activity and improve the targeted delivery of AEDs. However, their applications in the delivery of AEDs have not been adequately investigated. The objective of this study was to develop a nano-scale delivery system to improve the solubility and brain penetration of the antiepileptic drug lamotrigine (LTG).

METHODS

LTG-loaded Pluronic(®) P123 (P123) polymeric micelles (P123/LTG) were prepared by thin-film hydration, and brain penetration capability of the nanocarrier was evaluated.

RESULTS

The mean encapsulating efficiency for the optimized formulation was 98.07%; drug-loading was 5.63%, and particle size was 18.73 nm. The solubility of LTG in P123/LTG can increase to 2.17 mg/mL, making it available as a solution. The in vitro release of LTG from P123LTG presented a sustained-release property. Compared with free LTG, the LTG-incorporated micelles accumulated more in the brain at 0.5, 1, and 4 hours after intravenous administration in rats. Pretreatment with systemic verapamil increased the rapid brain penetration of free LTG but not P123/LTG. Incorporating another P-gp substrate (Rhodamine 123) into P123 micelles also showed higher efficiency in penetrating the BBB in vitro and in vivo.

CONCLUSION

These results indicated that P123 micelles have the potential to overcome the activity of P-gp expressed on the BBB and therefore show potential for the targeted delivery of AEDs. Future studies are necessary to further evaluate the appropriateness of the nanocarrier to enhance the efficacy of AEDs.

Aqueous nanomicellar formulation for topical delivery of biotinylated lipid prodrug of acyclovir: formulation development and ocular biocompatibility

PURPOSE

The objective of this study was to develop a clear, aqueous nanomicellar formulation and evaluate its in vitro ocular biocompatibility as a novel carrier for topical ocular delivery of biotinylated lipid prodrug for the treatment of herpetic keratitis.

METHODS

Micellar formulation of Biotin-12Hydroxystearic acid-acyclovir (B-12HS-ACV) was prepared by solvent evaporation/film hydration method with two nonionic surfactants, vitamin E TPGS and octoxynol-40. The optimized formulation was characterized for various parameters including micelle size, polydispersity index (PDI), and zeta-potential and in vitro prodrug release. Human corneal epithelial cells (HCECs) were employed for studying the cytotoxicity of the formulation. Further, mRNA expression levels of various cytokines were also studied with quantitative real-time PCR (qPCR).

RESULTS

Average size was 10.46±0.05 nm with a PDI of 0.086 for blank nanomicelles, and 10.78±0.09 nm with a PDI of 0.075 for prodrug-loaded nanomicelles. Both unloaded and prodrug-loaded nanomicelles had low negative zeta potential. Prodrug encapsulation efficiency of mixed nanomicelles was calculated to be ∼90%. Transmission electron microscopy analysis revealed that nanomicelles were spherical, homogenous, and devoid of aggregates. B-12HS-ACV release from nanomicelles was slow with no significant burst effect. Results show a sustained release of the prodrug from nanomicelles over a period of 4 days. Neither the blank formulation nor the prodrug-loaded micellar formulation demonstrated any cytotoxic effects. Further, incubation of HCECs with blank and prodrug-loaded nanomicellar groups did not significantly alter the expression levels of IL-1β, IL-6, IL-8, IL-17, TNF-α, and IFN-γ.

CONCLUSIONS

In summary, a topical clear, aqueous nanomicellar formulation comprised of vitamin E TPGS and octoxynol-40 loaded with 0.1% B-12HS-ACV was successfully developed. B-12HS-ACV-loaded nanomicelles are small in size, spherical, and homogenous, without any aggregates. The micellar formulations were perfectly transparent similar to pure water. Ocular biocompatibility studies indicated that mixed nanomicelles were nontoxic and noninflammatory to corneal epithelial cells. Therefore, nanomicellar technology represents a promising strategy for the delivery of biotinylated lipid prodrugs of ACV.

A novel drug-phospholipid complex enriched with micelles: preparation and evaluation in vitro and in vivo

Mixed micelles are widely used to increase solubility and bioavailability of poorly soluble drugs. One promising antitumor drug candidate is 20(S)-protopanaxadiol (PPD), although its clinical application is limited by low water solubility and poor bioavailability after oral administration. In this study, we developed mixed micelles consisting of PPD-phospholipid complexes and Labrasol(®) and evaluated their potential for oral PPD absorption. Micelles were prepared using a solvent-evaporation method, and their physicochemical properties, including particle size, zeta potential, morphology, crystal type, drug loading, drug entrapment efficiency, and solubility, were characterized. Furthermore, in vitro release was investigated using the dialysis method, and transport and bioavailability of the mixed micelles were investigated through a Caco-2 cell monolayer and in vivo absorption studies performed in rats. Compared with the solubility of free PPD (3 μg/mL), the solubility of PPD in the prepared mixed micelles was 192.41 ± 1.13 μg/mL in water at room temperature. The in vitro release profiles showed a significant difference between the more rapid release of free PPD and the slower and more sustained release of the mixed micelles. At the end of a 4-hour transport study using Caco-2 cells, the apical-to-basolateral apparent permeability coefficients (P(app)) increased from (1.12 ± 0.21) × 10(6) cm/s to (1.78 ± 0.16) × 10(6) cm/s, while the basolateral-to-apical P(app) decreased from (2.42 ± 0.16) × 10(6) cm/s to (2.12 ± 0.32) × 10(6). In this pharmacokinetic study, compared with the bioavailability of free PPD (area under the curve [AUC](0-∞)), the bioavailability of PPD from the micelles (AUC(0-∞)) increased by approximately 216.36%. These results suggest that novel mixed micelles can significantly increase solubility, enhance absorption, and improve bioavailability. Thus, these prepared micelles might be potential carriers for oral PPD delivery in antitumor therapies.

A novel drug-phospholipid complex enriched with micelles: preparation and evaluation in vitro and in vivo

Mixed micelles are widely used to increase solubility and bioavailability of poorly soluble drugs. One promising antitumor drug candidate is 20(S)-protopanaxadiol (PPD), although its clinical application is limited by low water solubility and poor bioavailability after oral administration. In this study, we developed mixed micelles consisting of PPD–phospholipid complexes and Labrasol^® and evaluated their potential for oral PPD absorption. Micelles were prepared using a solvent-evaporation method, and their physicochemical properties, including particle size, zeta potential, morphology, crystal type, drug loading, drug entrapment efficiency, and solubility, were characterized. Furthermore, in vitro release was investigated using the dialysis method, and transport and bioavailability of the mixed micelles were investigated through a Caco-2 cell monolayer and in vivo absorption studies performed in rats. Compared with the solubility of free PPD (3 μg/mL), the solubility of PPD in the prepared mixed micelles was 192.41 ± 1.13 μg/mL in water at room temperature. The in vitro release profiles showed a significant difference between the more rapid release of free PPD and the slower and more sustained release of the mixed micelles. At the end of a 4-hour transport study using Caco-2 cells, the apical-to-basolateral apparent permeability coefficients (P_app) increased from (1.12 ± 0.21) × 10⁶ cm/s to (1.78 ± 0.16) × 10⁶ cm/s, while the basolateral-to-apical P_app decreased from (2.42 ± 0.16) × 10⁶ cm/s to (2.12 ± 0.32) × 10⁶. In this pharmacokinetic study, compared with the bioavailability of free PPD (area under the curve [AUC]_0–∞), the bioavailability of PPD from the micelles (AUC_0–∞) increased by approximately 216.36%. These results suggest that novel mixed micelles can significantly increase solubility, enhance absorption, and improve bioavailability. Thus, these prepared micelles might be potential carriers for oral PPD delivery in antitumor therapies.

Pluronic P105/F127 mixed micelles for the delivery of docetaxel against Taxol-resistant non-small cell lung cancer: optimization and in vitro, in vivo evaluation

The aim of this work was to establish a novel polymeric mixed micelle composed of Pluronic P105 and F127 copolymers loaded with the poorly soluble antitumor drug docetaxel (DTX) against Taxol-resistant non-small cell lung cancer. A central composite design was utilized to optimize the preparation process, helping to improve drug solubilization efficiency and micelle stability. Prepared by a thin-film hydration method, the average size of the optimized mixed micelle was 23 nm, with a 92.40% encapsulation ratio and a 1.81% drug-loading efficiency. The optimized formulation showed high storage stability in lyophilized form, with 95.7% of the drug content remaining after 6 months’ storage at 4°C. The in vitro cytotoxicity assay showed that the IC50 values for Taxotere^® and mixed micelles were similar for A549, while on A549/Taxol cell lines, DTX-loaded P105/F127 mixed micelles showed a superior hypersensitizing effect; their IC50 value (0.059 μg/mL) was greatly reduced compared to those of Taxotere injections (0.593 μg/mL). The in vivo pharmacokinetic study showed that the mixed-micelle formulation achieved a 1.85-fold longer mean residence time in circulation and a 3.82-fold larger area under the plasma concentration-time curve than Taxotere. In addition, therapeutic improvement of mixed micelles in vivo against A549/Taxol was obtained. The tumor inhibition rate of the micelles was 69.05%, versus 34.43% for Taxotere (P < 0.01). Therefore, it could be concluded from the results that DTX-loaded P105/F127 mixed micelles might serve as a potential antitumor drug delivery system to overcome multidrug resistance in lung cancer.

Utilisation of nanoparticle technology in cancer chemoresistance

The implementation of cytotoxic chemotherapeutic drugs in the fight against cancer has played an invariably essential role for minimizing the extent of tumour progression and/or metastases in the patient and thus allowing for longer event free survival periods following chemotherapy. However, such therapeutics are nonspecific and bring with them dose-dependent cumulative adverse effects which can severely exacerbate patient suffering. In addition, the emergence of innate and/or acquired chemoresistance to the exposed cytotoxic agents undoubtedly serves to thwart effective clinical efficacy of chemotherapy in the cancer patient. The advent of nanotechnology has led to the development of a myriad of nanoparticle-based strategies with the specific goal to overcome such therapeutic hurdles in multiple cancer conditions. This paper aims to provide a brief overview and recollection of all the latest advances in the last few years concerning the application of nanoparticle technology to enhance the safe and effective delivery of chemotherapeutic agents to the tumour site, together with providing possible solutions to circumvent cancer chemoresistance in the clinical setting.