Preparation and optimization of biodegradable self-assembled PCL-PEG-PCL nano-sized micelles for drug delivery systems

Development of a Composite Hydrogel Containing Statistically Optimized PDGF-Loaded Polymeric Nanospheres for Skin Regeneration: In Vitro Evaluation and Stem Cell Differentiation Studies

Platelet-derived growth factor-BB (PDGF-BB) is a polypeptide growth factor generated by platelet granules faced to cytokines. It plays a role in forming and remodeling various tissue types, including epithelial tissue, through interaction with cell-surface receptors on most mesenchymal origin cells. However, it breaks down quickly in biological fluids, emphasizing the importance of preserving them from biodegradation. To address this challenge, we formulated and evaluated PDGF-encapsulated nanospheres (PD@PCEC) using polycaprolactone-polyethylene glycol-polycaprolactone. PD@PCECs were fabricated through the triple emulsion methodology and optimized by using the Box-Behnken design. The encapsulation efficiency (EE) of nanoencapsulated PDGF-BB was investigated concerning four variables: stirring rate (X1), stirring duration (X2), poly(vinyl alcohol) concentration (X3), and PDGF-BB concentration (X4). The selected optimized nanospheres were integrated into a gelatin-collagen scaffold (PD@PCEC@GC) and assessed for morphology, biocompatibility, in vitro release, and differentiation-inducing activity in human adipose-derived stem cells (hADSCs). The optimized PD@PCEC nanospheres exhibited a particle size of 177.9 ± 91 nm, a zeta potential of 5.2 mV, and an EE of 87.7 ± 0.44%. The release profile demonstrated approximately 85% of loaded PDGF-BB released during the first 360 h, with a sustained release over the entire 504 h period, maintaining bioactivity of 87.3%. The study also included an evaluation of the physicochemical properties of the scaffolds and an assessment of hADSC adhesion to the scaffold's surface. Additionally, hADSCs cultivated within the scaffold effectively differentiated into keratinocyte-like cells (KLCs) over 21 days, evidenced by morphological changes and upregulation of keratinocyte-specific genes, including cytokeratin 18, cytokeratin 19, and involucrin, at both transcriptional and protein levels.

PCL-based nanoparticles for doxorubicin-ezetimibe co-delivery: A combination therapy for prostate cancer using a drug repurposing strategy

INTRODUCTION

Drug repurposing is an effective strategy for identifying the use of approved drugs for new therapeutic purposes. This strategy has received particular attention in the development of cancer chemotherapy. Considering that a growing body of evidence suggesting the cholesterol-lowering drug ezetimibe (EZ) may prevent the progression of prostate cancer, we investigated the effect of EZ alone and in combination with doxorubicin (DOX) on prostate cancer treatment.

METHODS

In this study, DOX and EZ were encapsulated within a PCL-based biodegradable nanoparticle. The physicochemical properties of drug containing nanoparticle based on PCL-PEG-PCL triblock copolymer (PCEC) have been exactly determined. The encapsulation efficiency and release behavior of DOX and EZ were also studied at two different pHs and temperatures.

RESULTS

The average size of nanoparticles (NPs) observed by field emission scanning electron microscopy (FE-SEM) was around 82±23.80 nm, 59.7±18.7 nm, and 67.6±23.8 nm for EZ@PCEC, DOX@PCEC, and DOX+EZ@PCEC NPs, respectively, which had a spherical morphology. In addition, DLS measurement showed a monomodal size distribution of around 319.9, 166.8, and 203 nm hydrodynamic diameters and negative zeta potential (-30.3, -6.14, and -43.8) mV for EZ@PCEC, DOX@PCEC, and DOX+EZ@PCEC NPs, respectively. The drugs were released from the NPs sustainably in a pH and temperature-dependent manner. Based on the MTT assay results, PCEC copolymer exhibited negligible cytotoxicity on the PC3 cell line. Therefore, PCEC was a biocompatible and suitable nano-vehicle for this study. The cytotoxicity of the DOX-EZ-loaded NPs on the PC3 cell line was higher than that of NPs loaded with single drugs. All the data confirmed the synergistic effect of EZ in combination with DOX as an anticancer drug. Furthermore, fluorescent microscopy and DAPI staining were performed to show the cellular uptake, and morphological changes-induced apoptosis of treated cells.

CONCLUSION

Overall, the data from the experiments represented the successful preparation of the nanocarriers with high encapsulation efficacy. The designed nanocarriers could serve as an ideal candidate for combination therapy of cancer. The results corroborated each other and presented successful EZ and DOX formulations containing PCEC NPs and their efficiency in treating prostate cancer.

Nanoscale self-assembly: concepts, applications and challenges

Self-assembly offers unique possibilities for fabricating nanostructures, with different morphologies and properties, typically from vapour or liquid phase precursors. Molecular units, nanoparticles, biological molecules and other discrete elements can spontaneously organise or form via interactions at the nanoscale. Currently, nanoscale self-assembly finds applications in a wide variety of areas including carbon nanomaterials and semiconductor nanowires, semiconductor heterojunctions and superlattices, the deposition of quantum dots, drug delivery, such as mRNA-based vaccines, and modern integrated circuits and nanoelectronics, to name a few. Recent advancements in drug delivery, silicon nanoelectronics, lasers and nanotechnology in general, owing to nanoscale self-assembly, coupled with its versatility, simplicity and scalability, have highlighted its importance and potential for fabricating more complex nanostructures with advanced functionalities in the future. This review aims to provide readers with concise information about the basic concepts of nanoscale self-assembly, its applications to date, and future outlook. First, an overview of various self-assembly techniques such as vapour deposition, colloidal growth, molecular self-assembly and directed self-assembly/hybrid approaches are discussed. Applications in diverse fields involving specific examples of nanoscale self-assembly then highlight the state of the art and finally, the future outlook for nanoscale self-assembly and potential for more complex nanomaterial assemblies in the future as technological functionality increases.

Targeted drug delivery via folate decorated nanocarriers based on linear polymer for treatment of breast cancer

In this project, a biocompatible block copolymer including poly ethylene glycol and poly caprolactone was synthesized using ring-opening reaction. Then, the copolymer was conjugated to folic acid using lysine as a linker. Also, curcumin (CUR) was used as a therapeutic anticancer agent. Nanoprecipitation method was used to prepare CUR-loaded polymeric micelles. Different methods including Fourier-transform infrared spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering (DLS) were used to characterize the prepared nanocarriers (NCs). MTT assay and hemolysis assay were used to evaluate in vitro anticancer efficiency and biocompatibility of the prepared NCs, respectively. The results proved efficiency of NCs as a drug delivery system (DDS) in various aspects such as physicochemical properties and biocompatibility. Also, in vivo results showed that NCs did not show any severe weight loss and side effects on mice, and the anti-cancer study results of the CUR-loaded NCs proved that the conjugation of folic acid on the surface of NCs as a targeting agent could increase the therapeutic efficacy of CUR.

Effects of various media on micellization, adsorption and thermodynamic behaviour of imipramine hydrochloride and antimicrobial surfactant mixtures

The effect of various media (aqueous, NaCl, urea (U) and thiourea (TU)) on the micellization and adsorption activity of varied mixtures of imipramine hydrochloride (IMP) and benzethonium chloride (BZCl) is investigated via tensiometry. In an aqueous medium, the interactions between IMP and BZCl are also evaluated using UV-visible and FTIR spectroscopy. The interaction between components increases with increased mole fraction (α 1) of BZCl in the mixed system (IMP + BZCl). Different parameters, such as micellar and the mixed monolayer component composition, the interaction parameters of the solution and the interface, the activity coefficients of the components in solution and at the interface, and thermodynamic parameters, are computed using different proposed theoretical models (i.e. Clint, Motomura, Rubingh and Rosen). The cmc values obtained for the pure components and mixtures (IMP + BZCl) of all the compositions are found to be less in NaCl than in the aqueous solution while found more in the presence of U or TU. TU is more effective in increasing the cmc of the pure and mixed systems than U. The Gibbs free energy ( Δ G mic ∘ ) values of the studied pure and mixed systems are negative, showing the spontaneous nature of the reaction.

Non-Isothermal Crystallization Kinetics of Poly(ethylene glycol) and Poly(ethylene glycol)-B-Poly(ε-caprolactone) by Flash DSC Analysis

The non-isothermal crystallization behaviors of poly (ethylene glycol) (PEG) and poly (ethylene glycol)-b-poly(ε-caprolactone) (PEG-PCL) were investigated through a commercially available chip-calorimeter Flash DSC2+. The non-isothermal crystallization data under different cooling rates were analyzed by the Ozawa model, modified Avrami model, and Mo model. The results of the non-isothermal crystallization showed that the PCL block crystallized first, followed by the crystallization of the PEG block when the cooling rate was 50-200 K/s. However, only the PEG block can crystallize when the cooling rate is 300-600 K/s. The crystallization of PEG-PCL is completely inhibited when the cooling rate is 1000 K/s. The modified Avrami and Ozawa models were found to describe the non-isothermal crystallization processes well. The growth methods of PEG and PEG-PCL are both three-dimensional spherulitic growth. The Mo model shows that the crystallization rate of PEG is greater than that of PEG-PCL.

Functionalized Particles Designed for Targeted Delivery

Pure bioactive compounds alone can only be exceptionally administered in medical treatment. Usually, drugs are produced as various forms of active compounds and auxiliary substances, combinations assuring the desired healing functions. One of the important drug forms is represented by a combination of active substances and particle-shaped polymer in the nano- or micrometer size range. The review describes recent progress in this field balanced with basic information. After a brief introduction, the paper presents a concise overview of polymers used as components of nano- and microparticle drug carriers. Thereafter, progress in direct synthesis of polymer particles with functional groups is discussed. A section is devoted to formation of particles by self-assembly of homo- and copolymer-bearing functional groups. Special attention is focused on modification of the primary functional groups introduced during particle preparation, including introduction of ligands promoting anchorage of particles onto the chosen living cell types by interactions with specific receptors present in cell membranes. Particular attention is focused on progress in methods suitable for preparation of particles loaded with bioactive substances. The review ends with a brief discussion of the still not answered questions and unsolved problems.