Cell Permeating Nano-Complexes of Amphiphilic Polyelectrolytes Enhance Solubility, Stability, and Anti-Cancer Efficacy of Curcumin

Design of Cationic Lipids with Acetal Linkers: Conformational Preferences, Hydrolytic Stability, and High Drug-Loading Abilities

Lipids are key constituents of numerous biomedical drug delivery technologies. Here, we present the design, synthesis and biophysical characterizations of a library of cationic lipids containing an acetal residue in their linker region. These cationic acetal lipids (CALs) were conveniently prepared through a trans-acetalization protocol from commercially available precursors. NMR studies highlighted the conformational rigidity at the acetal residue and the high hydrolytic stability of these CALs. Fluorescence anisotropy studies revealed that the CAL with a pyridinium headgroup (CAL1) formed highly cohesive vesicular aggregates in water. These structural and self-assembly features of the CAL1 allowed up to 196 % w/w loading of curcumin (Cur) as a representative hydrophobic drug. A reconstitutable formulation of Cur was obtained as a result, which could deliver the drug inside mammalian cells with very high efficiency. The hemocompatibility and cytocompatibility of CAL1 was significantly enhanced by creating a coating of polydopamine (PDA) onto its vesicular assemblies to produce hybrid lipid-polymer nanocapsules. This work demonstrates rapid access to the useful synthetic lipid formulations with high potential in drug and gene delivery applications.

Oral non-viral gene delivery platforms for therapeutic applications

Since gene therapy can regulate gene and protein expression directly, it has a great potential to prevent or treat a variety of genetic or acquired diseases through vaccines such as viral infections, cystic fibrosis, and cancer. Owing to their high efficacy, in vivo gene therapy trials are usually conducted intravenously, which is usually costly and invasive. There are several advantages to oral drug administration over intravenous injections, such as better patient compliance, ease of use, and lower cost. However, gene therapy is successful if the oligonucleotides can cross the cell membrane easily and reach the nucleus after the endosomal escape. In order to accomplish this task and deliver the cargo to the intended location, appropriate delivery systems should be introduced. This review summarizes oral delivery systems developed for effective gene delivery, vaccination, and treatment of various diseases. Studies have also shown that oral delivery approaches are potentially applicable to treat various diseases, especially inflammatory bowel disease, stomach, and colorectal cancers. Also, the current review provides an update overview on the development of non-viral and oral gene delivery techniques for gene therapy and vaccination purposes.

Peptide-functionalised magnetic silk nanoparticles produced by a swirl mixer for enhanced anticancer activity of ASC-J9

Silk fibroin is an FDA approved biopolymer for clinical applications with great potential in nanomedicine. However, silk-based nanoformulations are still facing several challenges in processing and drug delivery efficiency (such as reproducibility and targetability), especially in cancer therapy. To address these challenges, robust and controllable production methods are required for generating nanocarriers with desired properties. This study aimed to develop a novel method for the production of peptide-functionalized magnetic silk nanoparticles with higher selectivity for cancer cells for targeted delivery of the hydrophobic anticancer agent ASC-J9. A new microfluidic device with a swirl mixer was designed to fabricate magnetic silk nanoparticles (MSNP) with desired size and narrow size distribution. The surface of MSNPs was functionalized with a cationic amphiphilic anticancer peptide, G(IIKK)₃I-NH₂ (G3), to enhance their selectivity towards cancer cells. The G3-MSNPs increased the cellular uptake and anticancer activity of G3 in HCT 116 colorectal cancer cells compared to free G3. Moreover, the G3-MSNPs exhibited considerably higher cellular uptake and cytotoxicity in HCT 116 colorectal cancer cells compared to normal cells (HDFs). Encapsulating ASC-J9 in G3-MSNPs resulted in augmented anticancer activity compared to free ASC-J9 and non-functionalized ASC-J9 loaded MSNPs within its biological half-life. Hence, functionalizing MSNPs with G3 enabled targeted delivery of ASC-J9 to cancer cells and enhanced its anticancer effect. Functionalization of nanoparticles with anticancer peptides could be regarded as a new strategy for targeted delivery and enhanced efficiency of anticancer drugs. Furthermore, the microfluidic device introduced in this paper offers a robust and reproducible method for fabrication of small sized homogenous nanoparticles.

K. S, Panigrahi NR, Mishra RK, Saraogi I. Amphiphilic Small-Molecule Assemblies to Enhance the Solubility and Stability of Hydrophobic Drugs

Amphiphilic assemblies made from diverse synthetic building blocks are well known for their biomedical applications. Here, we report the synthesis of gemini-type amphiphilic molecules that form stable assemblies in water. The assembly property of molecule M2 in aqueous solutions was first inferred from peak broadening observed in the proton NMR spectrum. This was supported by dynamic light scattering and transmission electron microscopy analysis. The assembly formed from M2 (M2agg) was used to solubilize the hydrophobic drugs curcumin and doxorubicin at physiological pH. M2agg was able to effectively solubilize curcumin as well as protect it from degradation under UV irradiation. Upon solubilization in M2agg, curcumin showed excellent cell permeability and higher toxicity to cancer cells over normal cells, probably because of enhanced cellular uptake and increased stability. M2agg also showed pH-dependent release of doxorubicin, resulting in controlled toxicity on cancer cell lines, making it a promising candidate for the selective delivery of drugs to cancer cells.

Enhancing Aqueous Solubility and Antibacterial Activity of Curcumin by Complexing with Cell-Penetrating Octaarginine

Bacterial resistance to antimicrobial drugs is one of the biggest threats to human health and novel drugs, and strategies are needed to obviate this resistance crisis. An innovative strategy for designing novel antimicrobial drugs is based on the hybridization of an antimicrobial agent with a second functional entity. Here, we use a cell-penetrating peptide-octaarginine (R8) as the second functional entity and develop a complex or hybrid of R8 and curcumin that possibly targets the bacterial cell membrane. Minimum inhibitory concentration assays show that the antibacterial activity of the complex is enhanced in a synergistic manner and rapid killing kinetics are obtained, emphasizing a bactericidal mode of action. In addition, electron microscopy images reveal bacterial membrane disruption by the complex. The R8-curcumin complex also displays activity against HeLa cells.

Natural Oral Anticancer Medication in Small Ethanol Nanosomes Coated with a Natural Alkaline Polysaccharide

Oral medication is the most acceptable therapy to treat chronic diseases. Natural drugs and excipients have unique advantages, such as low cost and high safety. We first investigated modified ethanol nanosomes for tumor treatment via oral administration. We loaded curcumin (CM) into small ethanol nanosomes coated with the natural alkaline polysaccharide chitosan (CCSET) for increased absorption and bioavailability and enhanced efficacy against small cell lung cancer (SCLC). Compared to CM and noncoated ethanol nanosomes, CCSETs exhibited superior physicochemical, in vitro-in vivo kinetic, and absorptive properties and treatment efficacy at the cellular and animal levels. The interaction of CM and serum albumin (the quantitative binding force) was analyzed. The bioavailability of CCSET increased by 11.84-fold and the tumor growth inhibition rate increased markedly compared to CM. We first confirmed the effect of CM on SCLC stem cells, and CCSET greatly enhanced this action. We first reported that CM had an antitumor effect on SCLC at the animal level and that CCSET enhanced this effect. Natural alkaline polysaccharide-coated small ethanol nanosomes delivering natural medicine may be a potential oral anticancer strategy.

Dietary-phytochemical mediated reversion of cancer-specific splicing inhibits Warburg effect in head and neck cancer

BACKGROUND

The deregulated alternative splicing of key glycolytic enzyme, Pyruvate Kinase muscle isoenzyme (PKM) is implicated in metabolic adaptation of cancer cells. The splicing switch from normal PKM1 to cancer-specific PKM2 isoform allows the cancer cells to meet their energy and biosynthetic demands, thereby facilitating the cancer cells growth. We have investigated the largely unexplored epigenetic mechanism of PKM splicing switch in head and neck cancer (HNC) cells. Considering the reversible nature of epigenetic marks, we have also examined the utility of dietary-phytochemical in reverting the splicing switch from PKM2 to PKM1 isoform and thereby inhibition of HNC tumorigenesis.

METHODS

We present HNC-patients samples, showing the splicing-switch from PKM1-isoform to PKM2-isoform analyzed via immunoblotting and qRT-PCR. We performed methylated-DNA-immunoprecipitation to examine the DNA methylation level and chromatin-immunoprecipitation to assess the BORIS (Brother of Regulator of Imprinted Sites) recruitment and polII enrichment. The effect of dietary-phytochemical on the activity of denovo-DNA-methyltransferase-3b (DNMT3B) was detected by DNA-methyltransferase-activity assay. We also analyzed the Warburg effect and growth inhibition using lactate, glucose uptake assay, invasion assay, cell proliferation, and apoptosis assay. The global change in transcriptome upon dietary-phytochemical treatment was assayed using Human Transcriptome Array 2.0 (HTA2.0).

RESULTS

Here, we report the role of DNA-methylation mediated recruitment of the BORIS at exon-10 of PKM-gene regulating the alternative-splicing to generate the PKM2-splice-isoform in HNC. Notably, the reversal of Warburg effect was achieved by employing a dietary-phytochemical, which inhibits the DNMT3B, resulting in the reduced DNA-methylation at exon-10 and hence, PKM-splicing switch from cancer-specific PKM2 to normal PKM1. Global-transcriptome-analysis of dietary-phytochemical-treated cells revealed its effect on alternative splicing of various genes involved in HNC.

CONCLUSION

This study identifies the epigenetic mechanism of PKM-splicing switch in HNC and reports the role of dietary-phytochemical in reverting the splicing switch from cancer-specific PKM2 to normal PKM1-isoform and hence the reduced Warburg effect and growth inhibition of HNC. We envisage that this approach can provide an effective way to modulate cancer-specific-splicing and thereby aid in the treatment of HNC.

A nanogel based oral gene delivery system targeting SUMOylation machinery to combat gut inflammation

Poor success rates and challenges associated with the current therapeutic strategies of inflammatory bowel disease (IBD) have accelerated the emergence of gene therapy as an alternative treatment option with great promise. However, oral delivery of nucleic acids (NAs) to an inflamed colon is challenged by multiple barriers presented by the gastrointestinal, extracellular and intracellular compartments. Therefore, we screened a series of polyaspartic acid-derived amphiphilic cationic polymers with varied hydrophobicity for their ability to deliver NAs into mammalian cells. Using the most effective TAC6 polymer, we then engineered biocompatible and stable nanogels composed of polyplexes (TAC6, NA) and an anionic polymer, sodium polyaspartate, that were able to deliver the NAs across mammalian cells using caveolae-mediated cellular uptake. We then utilized these nanogels for oral delivery of PIAS1 (protein inhibitor of activated STAT1), a SUMO 3 ligase, encoding plasmid DNA since PIAS1 is a key nodal therapeutic target for IBD due to its ability to control NF-κB-mediated inflammatory signaling. We show that plasmid delivery using TAC6-derived nanogels diminished gut inflammation in a murine colitis model. Therefore, our study presents engineering of orally deliverable nanogels that can target SUMOylation machinery to combat gut inflammation with very high efficacy.

Prevention of breast cancer by dietary polyphenols-role of cancer stem cells

Breast cancer is a common malignancy with poor prognosis. Cancer cells are heterogeneous and cancer stem cells (CSCs) are primarily responsible for tumor relapse, treatment-resistance and metastasis, so for breast cancer stem cells (BCSCs). Diets are known to be associated with carcinogenesis. Food-derived polyphenols are able to attenuate the formation and virulence of BCSCs, implying that these compounds and their analogs might be promising agents for preventing breast cancer. In the present review, we summarized the origin and surface markers of BCSCs and possible mechanisms responsible for the inhibitory effects of polyphenols on BCSCs. The suppressive effects of common dietary polyphenols against BCSCs, such as curcumin, epigallocatechin gallate (EGCG) and related polyphenolic compounds were further discussed.

Emerging biomedical applications of polyaspartic acid-derived biodegradable polyelectrolytes and polyelectrolyte complexes

A summary of positive biomedical attributes of biodegradable polyelectrolytes (PELs) prepared from aspartic acid is provided. The utility of these PELs in emerging applications such as biomineralization modulators, antimycobacterials, biocompatible cell encapsulants and tissue adhesives is highlighted.

Synthesis of indocyanine green functionalized comblike poly(aspartic acid) derivatives for enhanced cancer cell ablation by targeting the endoplasmic reticulum

PTX-loaded comblike polymer PAsp-g-(PEG-ICG) micelles can effectively kill cancer cells via elevated endoplasmic reticulum stress under laser irradiation.

Optical Spectroscopic and Morphological Characterizations of Curcuminized Silk Biomaterials: A Perspective from Drug Stabilization

Silk protein fibroins have gained remarkable attention in recent years as a potential drug carrier in the developing medicinal field of research. In this work, the stability of anticancer agent curcumin in the presence of two different silk protein fibroins from nonmulberry Antheraea mylitta (Am) and mulberry Bombyx mori (Bm) has been examined, and the possible mechanism of stabilization in a physiologically relevant medium has also been explored. In solution phase, upon treatment with curcumin, the predominated β-sheet structure of Am is marginally altered, whereas in the case of Bm, a substantial structural changeover has been observed (from coil to β-sheet) to accommodate the hydrophobic drug. Also, the morphological assessments suggest that curcumin is nicely housed in the nanoscaffold of silk fibroin (SF). Consequently, the extent of degradation of curcumin is remarkably suppressed upon encapsulation with the SF. The dissimilarity in the binding patterns of curcumin with these silk proteins could be responsible for the observed difference in the stability orders. Curcumin binds the surface of Bm, whereas in Am, the drug is incorporated in the hydrophobic cavity, and as a consequence, the drug is effectively sequestered out of the aqueous medium. The increase in the fluorescence quantum yield upon interaction with the protein greatly modulates the excited-state intermolecular hydrogen atom transfer (ESIPT) process, which is in tune with a substantial increase in the lifetime of the excited-state of curcumin. The ESIPT is known to play a crucial role in the degradation of curcumin under physiological pH conditions, which perhaps implies its potential therapeutic activity in the presence of silk. The in-depth spectroscopic analyses of curcumin-SF complexes in aqueous medium can provide useful insights for further applicative developments in bioengineering.

Influence of the microwave technology on solid dispersions of mefenamic acid and flufenamic acid

The present studies were undertaken to develop solvent-free solid dispersions (SDs) for poorly soluble anti-inflammatory drugs mefenamic acid (MA) and flufenamic acid (FFA) in order to enhance their in vitro dissolution rate and in vivo anti-inflammatory effects. The SDs of MA and FFA were prepared using microwaves irradiation (MW) technique. Different carriers such as Pluronic F127^® (PL), Eudragit EPO^® (EPO), polyethylene glycol 4000 (PEG 4000) and Gelucire 50/13 (GLU) were used for the preparation of SDs. Prepared MW irradiated SDs were characterized physicochemically using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infra-red (FT-IR) spectroscopy, powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). The physicochemical characteristics and drug release profile of SDs were compared with pure drugs. The results of DSC, TGA, FT-IR, PXRD and SEM showed that SDs were successfully prepared. In vitro dissolution rate of MA and FFA was remarkably enhanced by SDs in comparison with pure MA and FFA. The SDs of MA and FFA prepared using PEG 400 showed higher drug release profile in comparison with those prepared using PL, EPO or GLU. The dissolution efficiency for MA-PEG SD and FFA-PEG SD was obtained as 61.40 and 59.18%, respectively. Optimized SDs were also evaluated for in vivo anti-inflammatory effects in male Wistar rats. The results showed significant % inhibition by MA-PEG (87.74% after 4 h) and FFA-PEG SDs (81.76% after 4 h) in comparison with pure MA (68.09% after 4 h) and pure FFA (55.27% after 4 h) (P<0.05). These results suggested that MW irradiated SDs of MA and FFA could be successfully used for the enhancement of in vitro dissolution rate and in vivo therapeutic efficacy of both drugs.

Cancer Chemoprevention by Phytochemicals: Nature's Healing Touch

Phytochemicals are an important part of traditional medicine and have been investigated in detail for possible inclusion in modern medicine as well. These compounds often serve as the backbone for the synthesis of novel therapeutic agents. For many years, phytochemicals have demonstrated encouraging activity against various human cancer models in pre-clinical assays. Here, we discuss select phytochemicals—curcumin, epigallocatechin-3-gallate (EGCG), resveratrol, plumbagin and honokiol—in the context of their reported effects on the processes of inflammation and oxidative stress, which play a key role in tumorigenesis. We also discuss the emerging evidence on modulation of tumor microenvironment by these phytochemicals which can possibly define their cancer-specific action. Finally, we provide recent updates on how low bioavailability, a major concern with phytochemicals, is being circumvented and the general efficacy being improved, by synthesis of novel chemical analogs and nanoformulations.