In Vitro Assessment of Cisplatin/Hyaluronan Complex for Loco-Regional Chemotherapy.

Loco-regional chemotherapy is a strategy used to achieve more precise anticancer drug effect directly on tumor mass, while decreasing whole body exposure, which can lead to undesirable side effects. Thus, the loco-regional chemotherapy is conceptually similar to the targeted drug delivery systems for delivering chemotherapeutics to cancer cells in a certain location of the body. Recently, it has been demonstrated that a novel polymeric film containing the complex between cisplatin (cisPt) and hyaluronan (sodium salt of hyaluronic acid; NaHA) enhanced in vivo efficacy and safety of cisplatin (cisPt) by loco-regional delivery in pleural mesothelioma. Biologically, hyaluronic acid (HA) binds with the CD44 receptor, which is a transmembrane glycoprotein overexpressed by other cancer cells. Thus, administering both cisPt and hyaluronan together as a complex loco-regionally to the tumor site could target cancer cells locally and enhance treatment safety. A slight excess of hyaluronan was required to have more than 85% cisPt complexation. In cell monolayers (2D model) the cisPt/NaHA complex in solution demonstrated dose- and time-dependent cytotoxic effect by decreasing the viability of pancreatic, melanoma, and lung cell lines (they all express CD44). At the same concentration in solution, the complex was as effective as cisPt alone. However, when applied as film to melanoma spheroids (3D model), the complex was superior because it prevented the tumor spheroid growth and, more importantly, the formation of new cell colonies. Hence, cisPt/NaHA complex could work in preventing metastases loco-regionally and potentially avoiding systemic relapses.

Enzyme selection, optimization, and production toward biodegradation of post-consumer poly(ethylene terephthalate) at scale.

Poly(ethylene terephthalate) (PET) is one of the world's most widely used polyester plastics. Due to its chemical stability, PET is extremely difficult to hydrolyze in a natural environment. Recent discoveries in new polyester hydrolases and breakthroughs in enzyme engineering strategies have inspired enormous research on biorecycling of PET. This study summarizes our research efforts toward large-scale, efficient, and economical biodegradation of post-consumer waste PET, including PET hydrolase selection and optimization, high-yield enzyme production, and high-capacity enzymatic degradation of post-consumer waste PET. First, genes encoding PETase and MHETase from Ideonella sakaiensis and the ICCG variant of leaf-branch compost cutinase (LCCICCG ) were codon-optimized and expressed in Escherichia coli BL21(DE3) for high-yield production. To further lower the enzyme production cost, a pelB leader sequence was fused to LCCICCG so that the enzyme can be secreted into the medium to facilitate recovery. To help bind the enzyme on the hydrophobic surface of PET, a substrate-binding module in a polyhydroxyalkanoate depolymerase from Alcaligenes faecalis (PBM) was fused to the C-terminus of LCCICCG . The resulting four different LCCICCG variants (LCC, PelB-LCC, LCC-PBM, and PelB-LCC-PBM), together with PETase and MHETase, were compared for PET degradation efficiency. A fed-batch fermentation process was developed to produce the target enzymes up to 1.2 g L-1 . Finally, the best enzyme, PelB-LCC, was selected and used for the efficient degradation of 200 g L-1 recycled PET in a well-controlled, stirred-tank reactor. The results will help develop an economical and scalable biorecycling process toward a circular PET economy.

Polymeric in situ forming depots for long-acting drug delivery systems.

Polymeric in situ forming depots have emerged as highly promising drug delivery systems for long-acting applications. Their effectiveness is attributed to essential characteristics such as biocompatibility, biodegradability, and the ability to form a stable gel or solid upon injection. Moreover, they provide added versatility by complementing existing polymeric drug delivery systems like micro- and nanoparticles. The formulation's low viscosity facilitates manufacturing unit operations and enhances delivery efficiency, as it can be easily administered via hypodermic needles. The release mechanism of drugs from these systems can be predetermined using various functional polymers. To enable unique depot design, numerous strategies involving physiological and chemical stimuli have been explored. Important assessment criteria for in situ forming depots include biocompatibility, gel strength and syringeability, texture, biodegradation, release profile, and sterility. This review focuses on the fabrication approaches, key evaluation parameters, and pharmaceutical applications of in situ forming depots, considering perspectives from academia and industry. Additionally, insights about the future prospects of this technology are discussed.

Ibrutinib amorphous solid dispersions with enhanced dissolution at colonic pH for the localized treatment of colorectal cancer.

Colorectal cancer (CRC) is the second most leading cause of cancer-related deaths worldwide. Ibrutinib (IBR), the first in class bruton tyrosine kinase (BTK) inhibitor has promising anticancer activity. In this study, we aimed to develop a hot melt extrusion based amorphous solid dispersions (ASD) of IBR with enhanced dissolution at colonic pH and assess the anticancer activity against colon cancer cell lines. Since colonic pH is higher in CRC patients compared to healthy individuals, Eudragit® FS100 was used as pH dependent polymeric matrix for colon enabled release of IBR. Poloxamer 407, TPGS and poly(2-ethyl-2-oxazoline) were screened as plasticizer and solubilizer to improve the processability and solubility. Solid state characterization and filament appearance confirmed that IBR was molecularly dispersed within FS100 + TPGS matrix. In-vitro drug release of ASD showed > 96% drug release within 6 h at colonic pH with no precipitation for 12 h. Contrary, crystalline IBR showed negligible release. ASD with TPGS showed significantly higher anticancer activity in 2D and multicellular 3D spheroids of colon carcinoma cell lines (HT-29 and HT-116). The outcomes of this research suggested that ASD with a pH dependent polymer is a promising strategy to improve solubility and an effective approach in colorectal cancer targeting.

Investigating Key Molecular Descriptors Affecting Particle Size: A Predictive Exemplary Approach for Self-Emulsifying System.

The self-nano/microemulsifying drug delivery system is one of the well-established techniques for enhancing the solubility of poorly water-soluble drug molecules. The ratio of oil:surfactant:cosolvent plays a key role in globule size on dispersion into water, but there is very limited information on how a drug molecule affects the size. The rationale of this project was to illustrate the correlation between the particle size of nanoemulsion droplets and molecular descriptors of a drug. In the study, a self-nanoemulsifying preconcentrate containing drug with medium chain triglycerides (oil), dimethylacetamide (DMA, cosolvent), and Kolliphor EL (surfactant) was prepared for 40 drug molecules with diverse physicochemical properties. The self-nanoemulsifying preconcentrate was dispersed in water, and dynamic light scattering particle size was analyzed. A majority of drugs showed a significant increase in globule size compared to blank formulation, while few drugs showed a stark reduction in globule size. It is interesting to understand the attributes of molecules driving the self-emulsification and the diameter of nanoglobules. A systematic correlation of resultant particle size with 1D, 2D, and 3D molecular descriptors (overall more than 700 descriptors) was carried out for the data set using the PaDEL tool kit. The data compilation, curation, and analysis were performed using the SIMCA14 software. In the process of molecular descriptors screening, thereafter curation, 50 descriptors were selected using the genetic algorithm screening. The PLS-DA statistical method was employed for conversion of data into binomial systems. Final group of 5 descriptors: SpMiSpMin2_Bhe, RNCS, TDB9i, JG17, and ETA_Shape showed the correlation with particle size and classifying the drug molecules facilitating increase or decrease in particle size.

Drug delivery challenges and formulation aspects of proteolysis targeting chimera (PROTACs).

Proteolysis targeting chimeras (PROTACs) have been extensively explored for targeted proteasomal degradation of disease-related proteins with enormous potential in the treatment of intractable diseases. However, PROTACs are poorly soluble and permeable bulky molecules facing several bioavailability challenges irrespective of the route of administration. Our review lays out crucial challenges in the delivery of target protein degraders and nanoformulation approaches to overcome physicochemical and biological hurdles that can aid in transporting these target-protein degraders to the disease site. We have elaborated on the current formulation approaches and further highlighted the prospective delivery strategies that could be probed for disease-specific targeted delivery of PROTACs.

A Comprehensive Analysis of Myocarditis in Formerly Healthy Individuals Following SARS-CoV-2 Vaccination (COVID-19 Immunization).

Due to the rapid development of the coronavirus disease 2019 (COVID-19) pandemic, the Food and Drug Administration (FDA) expedited the authorization of immunizations to counteract life-threatening COVID-19 effects. COVID-19 immunization was seen as an essential component of surviving endemically with COVID-19. Although there were no major adverse event reports that mandated an early authorization of the mass vaccination approval in initial studies, a few significant adverse events were reported after real-world usage. The most prevalent adverse events are regional reactions, such as discomfort at the injection site. Anaphylactic shock and acute responses were quite infrequent. Current evidence strongly convince the community that the advantages of immunization outweigh the risks. The review investigates the potential adverse reaction in the form of myocarditis caused by the COVID-19 vaccine. Age, sexuality, vaccination type, clinical manifestations, and diagnostic modalities were among the confounding factors associated with vaccine-induced myocarditis. This picture depicts COVID-19 immunization-induced myocarditis and the treatment options available to practitioners. Further evaluation is needed to establish the underlying cause of this association. We compiled the most recent data on SARS-CoV-2 vaccine-induced myocarditis after reviewing available research. Information sources including PubMed and Google Scholar were evaluated retrospectively.

Understanding Consequences and Tradeoffs of Melt Processing as a Pretreatment for Enzymatic Depolymerization of Poly(ethylene terephthalate).

Melt extrusion pretreatment of poly(ethylene terephthalate) (PET) prior to enzymatic depolymerization with an unpurified leaf branch compost cutinase enzyme cocktail is explored to ascertain the efficiency gained by different processing methods on the enzymatic depolymerization of PET. Specific surface area (SSA) is investigated as a key factor in reducing depolymerization time. Higher SSA substrates (>5.6 mm2  mg-1 ) show higher depolymerization rates (≈0.88 g L-1 terephthalic acid [TPA] per day) and no induction phase, while lower SSA substrates (≈4.3, 4.4, and 5.6 mm2  mg-1 ) show, after an initial induction phase, similar depolymerization rates (≈0.46, 0.45, and 0.44 g L-1 TPA per day) despite increases in SSA of up to 30%. The mechanism of enzymatic depolymerization manifests in the appearance of anisotropic pitting. Longer incubation time used to overcome the induction phase in low SSA substrates allows for nearly full recovery of monomeric products, but manual pregrinding of extruded PET sharply increases SSA, depolymerization rate, and substrate crystallinity which may decrease the maximum recycled yield of the product materials. An estimate of the energy cost of increasing SSA is made and its effects on material properties are discussed. This work highlights key material structure and pretreatment aspects influencing the enzymatic recycling of PET.

Palmitoyl Carnitine-Anchored Nanoliposomes for Neovasculature-Specific Delivery of Gemcitabine Elaidate to Treat Pancreatic Cancer.

Being the fourth most fatal malignancy worldwide, pancreatic cancer is on track to become the second leading cause of cancer-related deaths in the United States by 2030. Gemcitabine is a first-line chemotherapeutic agent for pancreatic ductal adenocarcinoma (PDAC). Gemcitabine Elaidate (Gem Elaidate) is a lipophilic derivative which allows hENT1-independent intracellular delivery of gemcitabine and better pharmacokinetics and entrapment in a nanocarrier. Cancer cells and neovasculature are negatively charged compared to healthy cells. Palmitoyl-DL-carnitine chloride (PC) is a Protein kinase C (PKC) inhibitor which also provides a cationic surface charge to nanoliposomes for targeting tumor neovasculature and augmented anticancer potency. The objectives of our study are: (a) to develop and characterize a PKC inhibitor-anchored Gem Elaidate-loaded PEGylated nanoliposome (PGPLs) and (b) to investigate the anticancer activity of Gem Elaidate and PGPLs in 2D and 3D models of pancreatic cancer. The optimized PGPLs resulted in a particle size of 80 ± 2.31 nm, a polydispersity index of 0.15 ± 0.05 and a ζ-potential of +31.6 ± 3.54 mV, with a 93.25% encapsulation efficiency of Gem Elaidate in PGPLs. Our results demonstrate higher cellular uptake, inhibition in migration, as well as angiogenesis potential and significant apoptosis induced by PGPLs in 3D multicellular tumor spheroids of pancreatic cancer cells. Hence, PGPLs could be an effective and novel nanoformulation for the neovasculature-specific delivery of Gemcitabine Elaidate to treat PDAC.

Co-delivery of cisplatin and siRNA through hybrid nanocarrier platform for masking resistance to chemotherapy in lung cancer.

The resistance of cancer cells to chemotherapy has presented a formidable challenge. The current research aims at evaluating whether silencing of the cisplatin efflux promoter gene ABCC3 using siRNA co-loaded with the drug in a nanocarrier improves its efficacy in non-small cell lung cancer (NSCLC). Hybrid nanocarriers (HNCs) comprising lipids and poly(lactic acid-polyethylene glycol) di-block copolymer (PEG-PLA) were prepared for achieving the simultaneous delivery of cisplatin caprylate and ABCC3-siRNA to the cancer cells. PEGylation of the formulated HNCs was carried out using post-insertion technique for imparting long circulation characteristics to the carrier. The optimized formulation exhibited an entrapment efficiency of 71.9 ± 2.2% and 95.83 ± 0.39% for cisplatin caprylate and siRNA respectively. Further, the HNC was found to have hydrodynamic diameter of 153.2 ± 1.76 nm and + 25.39 ± 0.49 mV zeta potential. Morphological evaluation using cryo transmission electron microscopy confirmed the presence of lipid bilayer surrounding the polymeric core in HNCs. The in vitro cellular uptake studies showed improved uptake, while cell viability studies of the co-loaded formulation in A549 cell-line indicated significantly improved cytotoxic potential when compared with drug solution and drug-loaded HNCs; cell cycle analysis indicated increased percentage of cell arrest in G2-M phase compared with drug-loaded HNCs. Further, the gene knock-down study showed that silencing of ABCC3 mRNA might be improved in vitro efficacy of the formulation. The optimized cisplatin and ABCC3 siRNA co-loaded formulation presented significantly increased half-life and tumour regression in A549 xenograft model in BALB/c nude mice. In conclusion, siRNA co-loaded formulation presented reduced drug resistance and increased efficacy, which might be promising for the current cisplatin-based treatments in NSCLC.

Co(II) Macrocyclic Complexes Appended with Fluorophores as paraCEST and cellCEST Agents.

Four high-spin macrocyclic Co(II) complexes with hydroxypropyl or amide pendants and appended coumarin or carbostyril fluorophores were prepared as CEST (chemical exchange saturation transfer) MRI probes. The complexes were studied in solution as paramagnetic CEST (paraCEST) agents and after loading into Saccharomyces cerevisiae yeast cells as cell-based CEST (cellCEST) agents. The fluorophores attached to the complexes through an amide linkage imparted an unusual pH dependence to the paraCEST properties of all four complexes through of ionization of a group that was attributed to the amide NH linker. The furthest shifted CEST peak for the hydroxypropyl-based complexes changed by ∼90 ppm upon increasing the pH from 5 to 7.5. At acidic pH, the Co(II) complexes exhibited three to four CEST peaks with the most highly shifted CEST peak at 200 ppm. The complexes demonstrated substantial paramagnetic water proton shifts which is a requirement for the development of cellCEST agents. The large shift in the proton resonance was attributed to an inner-sphere water at neutral pH, as shown by variable temperature 17O NMR spectroscopy studies. Labeling of yeast with one of these paraCEST agents was optimized with fluorescence microscopy and validated by using ICP mass spectrometry quantitation of cobalt. A weak asymmetry in the Z-spectra was observed in the yeast labeled with a Co(II) complex, toward a cellCEST effect, although the Co(II) complexes were toxic to the cells at the concentrations necessary for observation of cellCEST.

Binding and Release of FeIII Complexes from Glucan Particles for the Delivery of T1 MRI Contrast Agents.

Yeast-derived ß-glucan particles (GPs) are a class of microcarriers under development for the delivery of drugs and imaging agents to immune-system cells for theranostic approaches. However, the encapsulation of hydrophilic imaging agents in the porous GPs is challenging. Here, we show that the unique coordination chemistry of FeIII -based macrocyclic T1 MRI contrast agents permits facile encapsulation in GPs. Remarkably, GPs labeled with the simple FeIII complexes are stable under physiologically relevant conditions, despite the absence of amphiphilic groups. In contrast to the free FeIII coordination complex, the labeled FeIII -GPs have lowered T1 relaxivity and act as a silenced form of the contrast agent. Addition of a fluorescent tag to the FeIII complex produces a bimodal agent to further enable tracking of the nanoparticles and to monitor release. Treatment of the iron-labeled GPs with a maltol chelator or with mildly acidic conditions releases the intact iron complex and restores enhanced T1 relaxation of the water protons.

MRI and fluorescence studies of Saccharomyces cerevisiae loaded with a bimodal Fe(III) T1 contrast agent.

Labeling of cells with paramagnetic metal complexes produces changes in MRI properties that have applications in cell tracking and identification. Here we show that fungi, specifically the budding yeast Saccharomyces cerevisiae, can be loaded with Fe(III) T1 contrast agents. Two Fe(III) macrocyclic complexes based on 1,4,7-triazacyclononane, with two pendant alcohol groups are prepared and studied as T1 relaxation MRI probes. To better visualize uptake and localization in the yeast cells, Fe(III) complexes have a fluorescent tag, consisting of either carbostyril or fluoromethyl coumarin. The Fe(III) complexes are robust towards dissociation and produce moderate T1 effects, despite lacking inner-sphere water ligands. Fluorescence microscopy and MRI T1 relaxation studies provide evidence of uptake of an Fe(III) complex into Saccharomyces cerevisiae upon electroporation.

Nanocarriers in effective pulmonary delivery of siRNA: current approaches and challenges.

Research on siRNA is increasing due to its wide applicability as a therapeutic agent in irreversible medical conditions. siRNA inhibits expression of the specific gene after its delivery from formulation to cytosol region of a cell. RNAi (RNA interference) is a mechanism by which siRNA is silencing gene expression for a particular disease. Numerous studies revealed that naked siRNA delivery is not preferred due to instability and poor pharmacokinetic performance. Nanocarriers based delivery of siRNA has the advantage to overcome physiological barriers and protect the integrity of siRNA from degradation by RNAase. Various diseases like lung cancer, cystic fibrosis, asthma, etc can be treated effectively by local lung delivery. The selective targeted therapeutic action in diseased organ and least off targeted cytotoxicity are the key benefits of pulmonary delivery. The current review highlights recent developments in pulmonary delivery of siRNA with novel nanosized formulation approach with the proven in vitro/in vivo applications.

Total Synthesis of the Proposed Structure of Mycobactin J.

The total synthesis of the proposed structure of mycobactin J (MJ), a metabolite of Mycobacterium tuberculosis, is presented. The highlights of the synthesis include a careful control of the Z-stereochemistry of the unsaturated long chain fatty acid, a biomimetic construction of the oxazoline building block and the carriage of an unprotected phenol throughout the synthesis.

pH triggered controlled drug delivery from contact lenses: Addressing the challenges of drug leaching during sterilization and storage.

In the present work a novel cyclosporine-loaded Eudragit S100 (pH-sensitive) nanoparticles-laden contact lenses were designed to provide sustained release of cyclosporine at therapeutic rates, without leaching of drug during sterilization and storage period (shelf life). The nanoparticles were prepared by Quasi-emulsion solvent diffusion technique using different weight ratios of cyclosporine to Eudragit S100. The contact lenses with direct drug entrapment were also fabricated (DL-50) for comparison. The percentage swelling and optical transparency of nanoparticles-laden contact lenses were improved in comparison to DL-50 lenses. The nanoparticles-laden contact lenses showed sustained drug release profiles, with inverse relationship to the amount of nanoparticles loaded in the contact lenses. It was interesting to note that nanoparticles form nanochannels/cavities after dissolution of Eudragit S 100 in tear fluid pH=7.4 (in vitro release study). This followed the precipitation of drug in hydrogel matrix of contact lenses. As the amount of nanoparticles loading increased, more number of cavities were formed, which caused the formation of large cavities in contact lens matrix. This in turn precipitated the drug. The nanoparticles-laden contact lenses with 1:1 (drug: Eudragit) weight ratio showed the most promising results of sustaining the drug release up to 156h, without affecting optical and physical properties of contact lenses. Packaging study confirmed that the drug was not leached in packaging solution (buffer, pH=6.5) from nanoparticles-laden lenses during shelf life period. In-vivo study in rabbit tear fluid showed sustained release up to 14days. The study revealed the application of pH-sensitive nanoparticles-laden contact lenses for controlled release of cyclosporine without altering the optical and physical properties of lens material.