Peripherally cross-linking the shell of core-shell polymer micelles decreases premature release of physically loaded combretastatin A4 in whole blood and increases its mean residence time and subsequent potency against primary murine breast tumors after IV administration

Mucin-mediated mucosal retention via end-terminal modified Pluronic F127-based hydrogel to increase drug accumulation in the lungs

Noninvasive lung drug delivery is critical for treating respiratory diseases. Pluronic-based copolymers have been used as multifunctional materials for medical and biological applications. However, the Pluronic F127-based hydrogel is rapidly degraded, adversely affecting the mechanical stability for prolonged drug release. Therefore, this study designed two thermosensitive copolymers by modifying the Pluronic F127 terminal groups with carboxyl (ADF127) or amine groups (EDF127) to improve the viscosity and storage modulus of drug formulations. β-alanine and ethylenediamine were conjugated at the terminal of Pluronic F127 using a two-step acetylation process, and the final copolymers were characterized using 1H nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectra. According to the 1H NMR spectra, Pluronic F127 was functionalized to form ADF127 and EDF127 with 85 % and 71 % functionalization degrees, respectively. Rheological studies revealed that the ADF127 (15 wt%) and EDF127 (15 wt%) viscosities increased from 1480 Pa.s (Pluronic F127) to 1700 Pa.s and 1800 Pa.s, respectively. Furthermore, the elastic modulus of ADF127 and EDF127 increased, compared with that of native Pluronic F127 with the addition of 5 % mucin, particularly for ADF127, thereby signifying the stronger adhesive nature of ADF127 and EDF127 with mucin. Additionally, ADF127 and EDF127 exhibited a decreased gelation temperature, decreasing from 33 °C (Pluronic F127 at 15 wt%) to 24 °C. Notably, the in vitro ADF127 and EDF127 drug release was prolonged (95 %; 48 h) by the hydrogel encapsulation of the liposome-Bdph combined with mucin, and the intermolecular hydrogen bonding between the mucin and the hydrogel increased the retention time and stiffness of the hydrogels. Furthermore, ADF127 and EDF127 incubated with NIH-3T3 cells exhibited biocompatibility within 2 mg/mL, compared with Pluronic F127. The nasal administration method was used to examine the biodistribution of the modified hydrogel carrying liposomes or exosomes with fluorescence using the IVIS system. Drug accumulation in the lungs decreased in the following order: ADF127 > EDF127 > liposomes or exosomes alone. These results indicated that the carboxyl group-modified Pluronic F127 enabled well-distributed drug accumulation in the lungs, which is beneficial for intranasal administration routes in treating diseases such as lung fibrosis.

Direct and Reverse Pluronic Micelles: Design and Characterization of Promising Drug Delivery Nanosystems

Pluronics are a family of amphiphilic block copolymers broadly explored in the pharmaceutical field. Under certain conditions, Pluronics self-assemble in different structures including nanosized direct and reverse micelles. This review provides an overview about the main parameters affecting the micellization process of Pluronics, such as polymer length, fragments distribution within the chain, solvents, additives and loading of cargo. Furthermore, it offers a guide about the most common techniques used to characterize the structure and properties of the micelles. Finally, it presents up-to-date approaches to improve the stability and drug loading of Pluronic micelles. Special attention is paid to reverse Pluronics and reverse micelles, currently underexplored in the literature. Pluronic micelles present a bright future as drug delivery agents. A smart design and thorough characterization will improve the transfer to clinical applications.

Formulation, Solubilization, and In Vitro Characterization of Quercetin-Incorporated Mixed Micelles of PEO-PPO-PEO Block Copolymers

Quercetin (QCN) is a plant polyphenol with a variety of medicinal effects. Poor water solubility, on the other hand, restricts its therapeutic effectiveness. The purpose of this study was to develop mixed micellar systems using two biocompatible amphiphilic PEO-PPO-PEO triblock copolymers, Pluronic P123 (EO₂₀-PO₇₀-EO₂₀) and Pluronic F88 (EO₁₀₄-PO₃₉-EO₁₀₄), in order to enhance the aqueous solubility and oral bioavailability of QCN drug. The critical micelle concentrations (CMCs) of mixed P123/F88 micellar solutions were investigated using UV-visible spectroscopy with pyrene as a probe. Mixed P123/F88 micelles have low CMCs, indicating that they have a stable micelle structure even when diluted. The solubility of QCN in aqueous mixed P123/F88 micellar solutions at different temperatures was investigated to better understand drug entrapment. The QCN solubility increased with increasing temperature in the mixed P123/F88 micellar system. The QCN-incorporated mixed P123/F88 micelles were prepared using the thin-film hydration method and were well characterized in terms of size and morphology, compatibility, in vitro release and antioxidant profile. In addition, the cell proliferation activity of the mixed micelles was evaluated in the MCF-7 cell line. The QCN-incorporated mixed P123/F88 micelles had a small particle size (< 25 nm) and a negative zeta potential with a spherical shape. The in vitro release behaviour of QCN from a mixed P123/F88 micellar system was slower and more sustained at physiological conditions. The oxidation resistance of QCN-incorporating mixed P123/F88 micelles was shown to be considerably higher than that of pure QCN. An in vitro cell proliferation study revealed that QCN-incorporated mixed micells were effective in inhibiting tumour cell growth. In conclusion, the QCN-incorporated mixed P123/F88 micelle may be a promising approach to increase QCN oral bioavailability, antioxidant activity, and cell viability.

Engineered nanomedicines for tumor vasculature blockade therapy

Tumor vasculature blockade therapy (TVBT), including angiogenesis inhibition, vascular disruption, and vascular infarction, provides a promising treatment modality for solid tumors. However, low selectivity, drug resistance, and possible severe side effects have limited the clinical transformation of TVBT. Engineered nanoparticles offer potential solutions, including prolonged circulation time, targeted transportation, and controlled release of TVBT agents. Moreover, engineered nanomedicines provide a promising combination platform of TVBT with chemotherapy, radiotherapy, photodynamic therapy, photothermal therapy, ultrasound therapy, and gene therapy. In this article, we offer a comprehensive summary of the current progress of engineered nanomedicines for TVBT and also discuss current deficiencies and future directions for TVBT development. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Obstructions in Nanoparticles Conveyance, Nano-Drug Retention, and EPR Effect in Cancer Therapies

In this chapter, the authors first review nano-devices that are mixtures of biologic molecules and synthetic polymers like nano-shells and nano-particles for the most encouraging applications for different cancer therapies. Nano-sized medications additionally spill especially into tumor tissue through penetrable tumor vessels and are then held in the tumor bed because of diminished lymphatic drainage. This procedure is known as the enhanced penetrability and retention (EPR) impact. Nonetheless, while the EPR impact is generally held to improve conveyance of nano-medications to tumors, it in certainty offers not exactly a 2-overlay increment in nano-drug conveyance contrasted with basic ordinary organs, bringing about medication concentration that is not adequate for restoring most malignant growths. In this chapter, the authors likewise review different obstructions for nano-sized medication conveyance and to make the conveyance of nano-sized medications to tumors progressively successful by expanding on the EPR impact..

Targeted-nanoliposomal combretastatin A4 (CA-4) as an efficient antivascular candidate in the metastatic cancer treatment

A number of antiangiogenic drugs have been approved by the Food and Drug Administration which are used in cancer therapy, and variety of other agents in several stages of clinical development or in preclinical assessment. Among these, combretastatin A4 (CA-4) is an under-researched inhibitor of angiogenesis that shows potential activity in the treatment of advanced tumors with migration capacity. However, its clinical application has been limited due to poor water solubility, low bioavailability, rapid metabolism, and systemic elimination. During the last decade, numerous investigations have been done to overcome these problems by using different CA-4 delivery systems or developing produgs of CA-4 or its structural analogs. Nevertheless, these strategies could not be efficient out of the undesired side effects on normal tissues. Nanoliposomal CA-4 not only benefits from the advantage of using liposomal drugs as opposed to free drugs but also can accumulate in the tumor site via specific targeting ligands, which leads to efficient targeting and enhancement of bioavailability. To the best of our knowledge, we consider an important attempt to understand different factors that might influence the CA-4 loading and release pattern of liposomes and the consequent results in tumor therapy. In this review, we shed light on various studied liposomal CA-4 formulations showing application thereof in cancer treatment.

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.

Development and optimization of methotrexate-loaded lipid-polymer hybrid nanoparticles for controlled drug delivery applications

Lipid-polymer hybrid nanoparticles (LPHNPs) are emerging platforms for drug delivery applications. In the present study, methotrexate loaded LPHNPs consisted of PLGA and Lipoid S100 were fabricated by employing a single-step modified nanoprecipitation method combined with self-assembly. A three factor, three level Box Behnken design using Design-Expert^® software was employed to access the influence of three independent variables on the particle size, drug entrapment and percent drug release. The optimized formulation was selected through numeric optimization approach. The results were supported with the ANOVA analysis, regression equations and response surface plots. Transmission electron microscope images indicated the nanosized and spherical shape of the LPHNPs with fair size distribution. The nanoparticles ranged from 176 to 308nm, which increased with increased polymer concentration. The increase in polymer and lipid concentration also increased the drug entrapment efficiency. The in vitro drug release was in range 70.34-91.95% and the release mechanism follow the Higuchi model (R²=0.9888) and Fickian diffusion (n<0.5). The in vitro cytotoxicity assay and confocal microscopy of the optimized formulation demonstrate the good safety and better internalization of the LPHNPs. The cell antiproliferation showed the spatial and controlled action of the nanoformulation as compared to the plain drug solution. The results suggest that LPHNPs can be a promising delivery system envisioned to safe, stable and potentially controlled delivery of methotrexate to the cancer cells to achieve better therapeutic outcomes.

Alginate/Poly(γ-glutamic Acid) Base Biocompatible Gel for Bone Tissue Engineering

A technique for synthesizing biocompatible hydrogels by cross-linking calcium-form poly(γ-glutamic acid), alginate sodium, and Pluronic F-127 was created, in which alginate can be cross-linked by Ca²⁺ from Ca–γ-PGA directly and γ-PGA molecules introduced into the alginate matrix to provide pH sensitivity and hemostasis. Mechanical properties, swelling behavior, and blood compatibility were investigated for each hydrogel compared with alginate and for γ-PGA hydrogel with the sodium form only. Adding F-127 improves mechanical properties efficiently and influences the temperature-sensitive swelling of the hydrogels but also has a minor effect on pH-sensitive swelling and promotes anticoagulation. MG-63 cells were used to test biocompatibility. Gelation occurred gradually through change in the elastic modulus as the release of calcium ions increased over time and caused ionic cross-linking, which promotes the elasticity of gel. In addition, the growth of MG-63 cells in the gel reflected nontoxicity. These results showed that this biocompatible scaffold has potential for application in bone materials.