The effect of π-Conjugation on the self-assembly of micelles and controlled cargo release

Design, fabrication, and evaluation of keratin and pectin incorporated supramolecular structured zero-oxidation state selenium nanogel blended 3D printed transdermal patch

This study investigates the synthesis of selenium nanoparticles (SeNPs), owing to the low cost and abundance of selenium. However, the toxicity of SeNP prompts the development of a selenium nanocomposite (SeNC) containing pectin, keratin, and ferulic acid to improve the bioactivity of Se[0]. Further, incorporating the SeNC in a suitable formulation for drug delivery as a transdermal patch was worth studying. Accordingly, various analytical techniques were used to characterize the SeNPs and the SeNC, confirming successful synthesis and encapsulation. The SeNC exhibited notable particle size of 448.2 ± 50.2 nm, high encapsulation efficiency (98.90 % ± 2.4 %), 28.1 ± 0.45 drug loading, and sustained drug release at pH 5.5. Zeta potential and XPS confirmed the zero-oxidation state. The supramolecular structure was evident from spectral analysis endorsing the semi-crystalline nature of the SeNC and SEM images showcasing flower-shaped structures. Further, the SeNC demonstrated sustained drug release (approx. 22 % at 48 h) and wound-healing potential in L929 fibroblast cells. Subsequently, the SeNC loaded into a gelling agent exhibited shear thinning properties and improved drug release by nearly 58 %. A 3D printed reservoir-type transdermal patch was developed utilizing the SeNC-loaded gel, surpassing commercially available patches in characteristics such as % moisture uptake, tensile strength, and hydrophobicity. The patch, evaluated through permeation studies and CAM assay, exhibited controlled drug release and angiogenic properties for enhanced wound healing. The study concludes that this patch can serve as a smart dressing with tailored functionality for different wound stages, offering a promising novel drug delivery system for wound healing.

pH and GSH dual-responsive drug-controlled nanomicelles for breast cancer treatment

We developed a pH/glutathione (GSH) dual-responsive smart nano-drug delivery system to achieve targeted release of a chemotherapeutic drug at breast tumor site. Doxorubicin (DOX) was linked to polyethylene glycol (PEG) through cis-aconitic anhydride (CA) and disulfide bonds (SS) to obtain the PEG-SS-CA-DOX prodrug, which spontaneously assembled into nanomicelles with a particle size of 48 ± 0.45 nm. PEG-SS-CA-DOX micelles achieved an efficient and rapid release of DOX under dual stimulation by weak acidic pH and high GSH content of tumors, with the release amount reaching 88.0% within 48 h. Cellular uptake experiments demonstrated that PEG-SS-CA-DOX micelles could efficiently transport DOX into cells and rapidly release it in the tumor microenvironment. In addition,in vivoantitumor experiments showed that PEG-SS-CA-DOX had a high inhibition rate of 70% against 4T1 breast cancer cells along with good biosafety. In conclusion, dual-responsive smart nanomicelles can achieve tumor-targeted drug delivery and specific drug release, thus improving therapeutic efficacy of drugs.

Non-apoptotic cell death induction via sapogenin based supramolecular particles

The discovery of novel chemotherapeutics that act through different mechanisms is critical for dealing with tumor heterogeneity and therapeutic resistance. We previously reported a saponin analog (AG-08) that induces non-canonical necrotic cell death and is auspicious for cancer therapy. Here, we describe that the key element in triggering this unique cell death mechanism of AG-08 is its ability to form supramolecular particles. These self-assembled particles are internalized via a different endocytosis pathway than those previously described. Microarray analysis suggested that AG-08 supramolecular structures affect several cell signaling pathways, including unfolded protein response, immune response, and oxidative stress. Finally, through investigation of its 18 analogs, we further determined the structural features required for the formation of particulate structures and the stimulation of the unprecedented cell death mechanism of AG-08. The unique results of AG-08 indicated that supramolecular assemblies of small molecules are promising for the field of anticancer drug development, although they have widely been accepted as nuisance in drug discovery studies.

3,4-Ethylenedioxythiophene (EDOT) End-Group Functionalized Poly-ε-caprolactone (PCL): Self-Assembly in Organic Solvents and Its Coincidentally Observed Peculiar Behavior in Thin Film and Protonated Media

End-group functionalization of homopolymers is a valuable way to produce high-fidelity nanostructured and functional soft materials when the structures obtained have the capacity for self-assembly (SA) encoded in their structural details. Herein, an end-functionalized PCL with a π-conjugated EDOT moiety, (EDOT-PCL), designed exclusively from hydrophobic domains, as a functional "hydrophobic amphiphile", was synthesized in the bulk ROP of ε-caprolactone. The experimental results obtained by spectroscopic methods, including NMR, UV-vis, and fluorescence, using DLS and by AFM, confirm that in solvents with extremely different polarities (chloroform and acetonitrile), EDOT-PCL presents an interaction- and structure-based bias, which is strong and selective enough to exert control over supramolecular packing, both in dispersions and in the film state. This leads to the diversity of SA structures, including spheroidal, straight, and helical rods, as well as orthorhombic single crystals, with solvent-dependent shapes and sizes, confirming that EDOT-PCL behaves as a "block-molecule". According to the results from AFM imaging, an unexpected transformation of micelle-type nanostructures into single 2D lamellar crystals, through breakout crystallization, took place by simple acetonitrile evaporation during the formation of the film on the mica support at room temperature. Moreover, EDOT-PCL's propensity for spontaneous oxidant-free oligomerization in acidic media was proposed as a presumptive answer for the unexpected appearance of blue color during its dissolution in CDCl3 at a high concentration. FT-IR, UV-vis, and fluorescence techniques were used to support this claim. Besides being intriguing and unforeseen, the experimental findings concerning EDOT-PCL have raised new and interesting questions that deserve to be addressed in future research.

Hyaluronic acid conjugates for topical treatment of skin cancer lesions

Skin cancer is one of the most common types of cancer in the United States and worldwide. Topical products are effective for treating cancerous skin lesions when surgery is not feasible. However, current topical products induce severe irritation, light-sensitivity, burning, scaling, and inflammation. Using hyaluronic acid (HA), we engineered clinically translatable polymer-drug conjugates of doxorubicin and camptothecin termed, DOxorubicin and Camptothecin Tailored at Optimal Ratios (DOCTOR) for topical treatment of skin cancers. When compared to the clinical standard, Efudex, DOCTOR exhibited high cancer-cell killing specificity with superior safety to healthy skin cells. In vivo studies confirmed its efficacy in treating cancerous lesions without irritation or systemic absorption. When tested on patient-derived primary cells and live-skin explants, DOCTOR killed the cancer with a selectivity as high as 21-fold over healthy skin tissue from the same donor. Collectively, DOCTOR provides a safe and potent option for treating skin cancer in the clinic.

Blood circulation stable doxorubicin prodrug nanoparticles containing hydrazone and thioketal moieties for antitumor chemotherapy

Prodrug nanoparticles with cleavable moieties sensitive to intracellular stimuli have drawn great attention on cancer chemotherapy. Herein, a reactive oxygen species (ROS)-responsive doxorubicin prodrug mPEG-Phe-TK-Phe-hyd-DOX was synthesized, in which hydrophilic methoxy poly(ethylene glycol) (mPEG) and hydrophobic anticancer drug doxorubicin (DOX) were conjugated with hydrazone (hyd) and ROS-responsive thioketal (TK) moieties. The ROS-responsiveness of prodrug was confirmed by proton nuclear magnetic resonance (¹H NMR) and dynamic light scattering (DLS). Unexpectedly, the results of in vitro drug release indicated that the hydrazone bond of prodrug nanoparticles was insensitive to pH, which may be due to the strong hydrophobicity, π-π interactions and cation-π interactions jointly inhibited the hydrolysis of hydrazone bonds under acidic conditions. The cellular uptake and in vitro anticancer study showed that ROS-responsive prodrug nanoparticles exhibited faster cellular uptake and better anticancer efficacy. The in vivo experiments showed that the ROS-responsive prodrug nanoparticles had comparable antitumor efficacy with free anticancer drug DOX and reduced organ toxicity. Our results provide novel idea of successfully design multi-stimuli-responsive nano-drug carrier.

Redox-responsive polyethyleneimine/tetrahedron DNA/doxorubicin nanocomplexes for deep cell/tissue penetration to overcome multidrug resistance

Deep penetration of nanomedicines to cancer cells and tissues is a main obstacle to conquering multidrug resistant (MDR) cancer. Here, we presented redox-responsive polyethyleneimine (disulfide cross-linked PEI, PSP)/tetrahedral DNA (TDNs)/doxorubicin (DOX) nanocomplexes (NCs), PSP/TDNs@DOX NCs, to accomplish tumor cell/tissue penetration for overcoming MDR. The NCs can respond to glutathione and DNase I to disassociate and release DOX. In vitro study revealed that the NCs (N/P = 30) with positive charge could be associated to cell membranes and "dig holes" on them, evoking the membrane-breaking for enhanced cellular internalization and bypassing endocytosis regardless of drug-resistant mechanism. Transwell and 3D tumor models study established that NCs can efficiently depart from cells through "holes leakage" and "infected" surrounding cells to penetrate into deep tumor tissues. In vivo study showed that the PSP/TDNs@DOX NCs exhibited superior tumor penetration and therapeutic efficiency in xenografted drug-resistant tumor mouse models including human breast (MCF-7/R) and ovarian (SKOV3/R) cancer, which represent MDR with characteristics of DOX efflux and impermeability, respectively.

Amphiphilic mPEG-Modified Oligo-Phenylalanine Nanoparticles Chemoenzymatically Synthesized via Papain

Amphiphilic mPEG-modified peptide nanoparticles were developed from oligo-phenylalanine (OPhe) nanoparticles (NPs) synthesized via papain. Tyndall effects indicate that OPhe NPs are amphiphobic. Addition of protein perturbants, sodium dodecyl sulfate (SDS), and urea, in the dispersion solution of OPhe NPs can significantly reduce the R _h,m value of NPs, from approximately 749.2 nm to about 200 nm. Therefore, the hydrophobic interaction and hydrogen bonding play major roles in maintaining the aggregation of OPhe NPs. Using the "grafting to" method, the methoxypolyethylene-modified OPhe NPs (mPEG-g-OPhe NPs) were synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), ¹H NMR, electrospray ionization mass spectrometry (ESI-MS), and dynamic light scattering (DLS). The attenuated total reflectance (ATR) spectrum of OPhe NPs and mPEG-g-OPhe NPs demonstrate that the secondary structures of these NPs are mainly β-type. mPEG-g-OPhe NPs can self-aggregate into spherical micelles both in water and cyclohexane. Increasing the chain length of the mPEG moiety, the critical micellar concentrations of mPEG-g-OPhe NPs increased in water but decreased in cyclohexane. The light stability, thermal stability, hydrolysis stability, and encapsulation stability of curcumin were significantly promoted by encapsulation in the micelles formed by mPEG-g-OPhe NPs. The protective effects regularly varied with the variations in the mPEG chain length of mPEG-g-OPhe NPs.