ZIF-8 nano confined protein-titanocene complex core-shell MOFs for efficient therapy of Neuroblastoma: Optimization, molecular dynamics and toxicity studies

Efficient internalization of nano architectured 177Lu-hyaluronic acid@ zirconium-based metal-organic framework for the treatment of neuroblastoma: Unravelling toxicity, stability, radiolabelling and bio-distribution

Zirconium-based metal-organic frameworks (UiO-66) have gained considerable attention owing to their versatile application. In the present research, UiO-66 was synthesized via a defect engineering approach, and its toxicity profile was explored. The synthesized nanomaterial was extensively characterized via spectroscopic methods such as FTIR and Raman spectroscopy, which confirmed the formation of the framework. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to determine the crystallinity, shape and size of the nanoformulations. Thermal gravimetric analysis, 1H NMR spectroscopy and Brunauer-Emmett-Teller (BET) surface area analysis were used to identify the differences between pristine and defective UiO-66. Furthermore, the synthesized MOF was exposed to various pH conditions, serum protein and DMEM. Drug loading and release studies were evaluated using 5-fluorouracil as a model anticancer drug. The synthesized MOFs were modified with hyaluronic acid via mussel-inspired polymerization to increase their uptake and stability. More importantly, the toxicity of the nanoformulation was investigated via various toxicity studies, such as hemolysis assays and cell viability assays, and was further supported by in vivo acute and subacute toxicity data obtained from Wistar rats. Radiolabelling and bio-distribution studies were also performed using 177Lu to explore the bio-distribution profile of UiO-66.

An Update on Emergent Nano-Therapeutic Strategies against Pediatric Brain Tumors

Pediatric brain tumors are the major cause of pediatric cancer mortality. They comprise a diverse group of tumors with different developmental origins, genetic profiles, therapeutic options, and outcomes. Despite many technological advancements, the treatment of pediatric brain cancers has remained a challenge. Treatment options for pediatric brain cancers have been ineffective due to non-specificity, inability to cross the blood-brain barrier, and causing off-target side effects. In recent years, nanotechnological advancements in the medical field have proven to be effective in curing challenging cancers like brain tumors. Moreover, nanoparticles have emerged successfully, particularly in carrying larger payloads, as well as their stability, safety, and efficacy monitoring. In the present review, we will emphasize pediatric brain cancers, barriers to treating these cancers, and novel treatment options.

Ameliorative anticancer effect of dendrimeric peptide modified liposomes of letrozole: In vitro and in vivo performance evaluations

Letrozole (LTZ) loaded dendrimeric nano-liposomes were prepared for targeted delivery to breast cancer cells. Surface modification with cationic peptide dendrimers (PDs) and a cancer specific ligand, transferrin (Tf), was attempted. Arginine-terminated PD (D-1) and Arginine-terminated, lipidated PD (D-2) were synthesized using Solid Phase Peptide Synthesis, purified by preparative HPLC and characterized using 1HNMR, MS and DSC analyses. Surface modification of drug loaded liposomes with Tf and/or PD was carried out. Formulations were characterized using FTIR, DSC, 1HNMR, XRD and TEM. Tf-conjugated LTZ liposomes (LTf) and Tf/D-2-conjugated LTZ liposomes (LTfD-2) showed greater cytotoxic potential (IC50 = 95.03 µg/mL and 23.75 µg/mL respectively) with enhanced cellular uptake in MCF7 cells compared to plain LTZ. Blocking studies of Tf (Tf-receptor mediated internalization) revealed decreased uptake of LTf and LTfD-2 confirming the role of Tf in uptake of Tf-conjugated liposomes. Intravenous treatment with LTfD-2 caused highest reduction in tumor volumes of female BALB/c-nude mice (145 mm3) compared to plain LTZ (605 mm3) and unconjugated LTZ liposomes (LP) (300 mm3). In vivo biodistribution studies revealed higher fluorescence in tumor tissue and liver of LTfD-2 treated mice than LTf or LP treatment. Immunohistochemical studies revealed greater apoptotic potential of LTfD-2 as indicated by TUNEL assay and ROS detection assay. The study reveals the superior therapeutic efficacy of the developed LTZ liposomal nanocarriers using PDs to enhance the transfection efficiency in addition to modifying the surface characteristics by attaching a targeting ligand for active drug targeting to breast cancer cells.

A tumor microenvironment-activatable nanoplatform with phycocyanin-assisted in-situ nanoagent generation for synergistic treatment of colorectal cancer

The in-situ generation of therapeutic agents in targeted lesions is promising for revolutionizing oncotherapy but is limited by the low production efficiency. Given the specific tumor microenvironment (TME) of colorectal cancer (CRC), i.e., mild acidity, overexpressed H2O2, glutathione (GSH) and H2S, we develop phycocyanin (PC) encapsulated PZTC/SS/HA nanocapsules (NCs) for TME-responsive, protein-assisted "turn-on'' therapy of CRC. The NCs are prepared by sequentially assembling Cu2+-tannic acid (TA) coordination shell, disulfide bond-bearing cross-linker, and hyaluronic acid (HA) on the sacrificial template ZIF-8, thus achieving pH-, GSH-responsiveness, and tumor targeting capability, respectively. Once reaching the CRC sites, the NCs can quickly disintegrate and release Cu2+ and PC, accompanied by subsequent endogenous H2S-triggered generation of copper sulfide (CuS). Significantly, the intracellular sulfidation process can be accelerated by PC, thereby enabling efficient photothermal therapy (PTT) under NIR-Ⅱ laser. Besides, Cu2+-associated chemodynamic therapy (CDT) can be simultaneously activated and enhanced by PTT-induced local hyperthermia and disulfide bond-induced GSH consumption. This CRC-targeted and TME-activated synergistic PTT/CDT strategy displays high therapeutic efficacy both in vitro and in vivo, which can open up a new avenue for biomolecule-assisted in-situ nanoagent generation and effective TME-responsive synergistic treatment of CRC.

Topical Micro-Emulsion of 5-Fluorouracil by a Twin Screw Processor-Based Novel Continuous Manufacturing Process for the Treatment of Skin Cancer: Preparation and In Vitro and In Vivo Evaluations

5-Fluorouracil (5-FU), a BCS class III drug, has low oral bioavailability and is cytotoxic in nature causing severe systemic side effects when administered through the intravenous route. Topical drug delivery could potentially mitigate the systemic side-effects. Microemulsions (MEs) would be an apt solution due to enhanced partitioning of the drug to the skin. However, conventional methods for preparing MEs are inefficient since they are not continuous and are very tedious and time-consuming processes hence revealing the need for the development of continuous manufacturing technology. In our study, 5-FU MEs were prepared using a continuous manufacturing Twin Screw Process (TSP) and its efficiency in the treatment of skin cancer was evaluated. Water-in-oil MEs were prepared using isopropyl myristate as the oil phase and Aerosol OT and Tween 80 as the surfactants. The average particle size was observed to be 178 nm. Transmission electron microscopy was employed to confirm the size and shape of the MEs. FTIR study proved no physical or chemical interaction between the excipients and the drug. In vitro drug release using vertical diffusion cells and ex vivo skin permeation studies showed that the drug was released sustainably and permeated across the skin, respectively. In in vitro cytotoxicity studies, 5-FU MEs were accessed in HaCat and A431 cell lines to determine percentage cell viability and IC50. Skin irritation and histopathological examination implied that the 5-FU MEs did not cause any significant irritation to the skin. In vivo pharmacodynamics studies in rats suggested that the optimised formulation was effective in treating squamous cell carcinoma (SCC). Therefore, 5-FU MEs efficiently overcame the various drawbacks faced during oral and intravenous drug delivery. Also, TSP proved to be a technique that overcomes the various problems associated with the conventional methods of preparing MEs.

One-Pot Facile Encapsulation of Dimethyloxallyl Glycine by Nanoscale Zeolitic Imidazolate Frameworks-8 for Enhancing Vascularized Bone Regeneration

In the process of bone tissue regeneration, regulation of osteogenesis-angiogenesis coupling is of great importance. Therefore, dimethyloxallyl glycine (DMOG) is loaded by nanoscale zeolitic imidazolate frameworks-8 (ZIF-8) to obtain a drug-loading system that can promote osteogenesis-angiogenesis coupling. Characterization of the drug-loading nanoparticles (DMOG@ZIF-8) reveals that DMOG is successfully loaded into ZIF-8 by two different methods, and the DMOG@ZIF-8 is prepared using the one-pot method (OD@ZIF-8) achieves higher loading efficiency and longer release time than those prepared using the post-loading method (PD@ZIF-8). In vitro studies found that DMOG@ZIF-8 significantly enhances the migration, tube formation, and angiogenesis-related protein secretion of human umbilical vein endothelial cells as well as the extracellular matrix mineralization, alkaline phosphatase activity, and osteogenesis-related protein secretion of bone marrow mesenchymal stem cells. Moreover, OD@ZIF-8 nanoparticles are more efficient than PD@ZIF-8 nanoparticles in induction of osteogenesis-angiogenesis coupling. Then, in vivo cranial critical defect model shows that the addition of OD@ZIF-8 significantly promotes vascularized bone formation as indicated by the results including microcomputed tomographic, histological and immunofluorescence staining, and so on. Taken together, loading ZIF-8 with DMOG may be a promising solution for critical-sized bone defect reconstruction and the one-pot method is preferred in the preparation of such drug-loading system.

Nanomedicines and cell-based therapies for embryonal tumors of the nervous system

Embryonal tumors of the nervous system are neoplasms predominantly affecting the pediatric population. Among the most common and aggressive ones are neuroblastoma (NB) and medulloblastoma (MB). NB is a sympathetic nervous system tumor, which is the most frequent extracranial solid pediatric cancer, usually detected in children under two. MB originates in the cerebellum and is one of the most lethal brain tumors in early childhood. Their tumorigenesis presents some similarities and both tumors often have treatment resistances and poor prognosis. High-risk (HR) patients require high dose chemotherapy cocktails associated with acute and long-term toxicities. Nanomedicine and cell therapy arise as potential solutions to improve the prognosis and quality of life of children suffering from these tumors. Indeed, nanomedicines have been demonstrated to efficiently reduce drug toxicity and improve drug efficacy. Moreover, these systems have been extensively studied in cancer research over the last few decades and an increasing number of anticancer nanocarriers for adult cancer treatment has reached the clinic. Among cell-based strategies, the clinically most advanced approach is chimeric-antigen receptor (CAR) T therapy for both pathologies, which is currently under investigation in phase I/II clinical trials. However, pediatric drug research is especially hampered due not only to ethical issues but also to the lack of efficient pre-clinical models and the inadequate design of clinical trials. This review provides an update on progress in the treatment of the main embryonal tumors of the nervous system using nanotechnology and cell-based therapies and discusses key issues behind the gap between preclinical studies and clinical trials in this specific area. Some directions to improve their translation into clinical practice and foster their development are also provided.

Advancements in cell membrane camouflaged nanoparticles: A bioinspired platform for cancer therapy

The idea of employing natural cell membranes as a coating medium for nanoparticles (NPs) endows man-made vectors with natural capabilities and benefits. In addition to retaining the physicochemical characteristics of the NPs, the biomimetic NPs also have the functionality of source cell membranes. It has emerged as a promising approach to enhancing the properties of NPs for drug delivery, immune evasion, imaging, cancer-targeting, and phototherapy sensitivity. Several studies have been reported with a multitude of approaches to reengineering the surface of NPs using biological membranes. Owing to their low immunogenicity and intriguing biomimetic properties, cell-membrane-based biohybrid delivery systems have recently gained a lot of interest as therapeutic delivery systems. This review summarises different kinds of biomimetic NPs reported so far, their fabrication aspects, and their application in the biomedical field. Finally, it briefs on the latest advances available in this biohybrid concept.

Effects of Zeolite as a Drug Delivery System on Cancer Therapy: A Systematic Review

Zeolites and zeolitic imidazolate frameworks (ZIFs) are widely studied as drug carrying nanoplatforms to enhance the specificity and efficacy of traditional anticancer drugs. At present, there is no other systematic review that assesses the potency of zeolites/ZIFs as anticancer drug carriers. Due to the porous nature and inherent pH-sensitive properties of zeolites/ZIFs, the compounds can entrap and selectively release anticancer drugs into the acidic tumor microenvironment. Therefore, it is valuable to provide a comprehensive overview of available evidence on the topic to identify the benefits of the compound as well as potential gaps in knowledge. The purpose of this study was to evaluate the potential therapeutic applications of zeolites/ZIFs as drug delivery systems delivering doxorubicin (DOX), 5-fluorouracil (5-FU), curcumin, cisplatin, and miR-34a. Following PRISMA guidelines, an exhaustive search of PubMed, Scopus, Embase, and Web of Science was conducted. No language or time limitations were used up to 25th August 2021. Only full text articles were selected that pertained to the usage of zeolites/ZIFs in delivering anticancer drugs. Initially, 1279 studies were identified, of which 572 duplicate records were excluded. After screening for the title, abstract, and full texts, 53 articles remained and were included in the qualitative synthesis. An Inter-Rater Reliability (IRR) test, which included a percent user agreement and reliability percent, was conducted for the 53 articles. The included studies suggest that anticancer drug-incorporated zeolites/ZIFs can be used as alternative treatment options to enhance the efficacy of cancer treatment by mitigating the drawbacks of drugs under conventional treatment.

A novel ratiometric fluorescence nanoprobe for sensitive determination of uric acid based on CD@ZIF-CuNC nanocomposites

A novel ratiometric fluorescence nanoprobe based on carbon dots (CDs) and Cu nanoclusters (CuNCs) was designed for the label-free determination of uric acid (UA). The metal-organic framework (MOF) encapsulated CuNCs (ZIF-CuNC), and nitrogen-doped CDs can self-assemble into well-defined spherical nanocomposites (CD@ZIF-CuNC) due to physical adsorption. Under the excitation wavelength of 360 nm, the CD@ZIF-CuNC nanocomposites exhibit two evident intrinsic emissions peaked at 460 nm (CDs) and 620 nm (ZIF-CuNC), respectively. In the presence of H₂O₂, the fluorescence of CD@ZIF-CuNC at 620 nm is quenched remarkably within 1 min, while little effect on the emission at 460 nm is observed. Therefore, taking the fluorescence at 620 nm as the report signal and 460 nm as the reference signal, ratiometric quantitative determination of H₂O₂ was achieved with a linear range of 1-100 μM and a detection limit of 0.30 μM. The CD@ZIF-CuNC nanoprobe was successfully applied to the determination of UA that is catalyzed by uricase to produce H₂O₂, obtaining the linear range of 1-30 μM and the detection limit of 0.33 μM. Eventually, this strategy has been successfully applied to the determination of UA in human urine samples. A novel and convenient CDs@ZIF-CuNCs-based nanoplatform was constructed for sensitive ratiometric fluorescence determination of UA.