A protein-sulfosalicylic acid/boswellic acids @metal-organic framework nanocomposite as anticancer drug delivery system

Acid-sensitive prodrugs; a promising approach for site-specific and targeted drug release

Drugs administered through conventional formulations are devoid of targeting and often spread to various undesired sites, leading to sub-lethal concentrations at the site of action and the emergence of undesired effects. Hence, therapeutic agents should be delivered in a controlled manner at target sites. Currently, stimuli-based drug delivery systems have demonstrated a remarkable potential for the site-specific delivery of therapeutic moieties. pH is one of the widely exploited stimuli for drug delivery as several pathogenic conditions such as tumor cells, infectious and inflammatory sites are characterized by a low pH environment. This review article aims to demonstrate various strategies employed in the design of acid-sensitive prodrugs, providing an overview of commercially available acid-sensitive prodrugs. Furthermore, we have compiled the progress made for the development of new acid-sensitive prodrugs currently undergoing clinical trials. These prodrugs include albumin-binding prodrugs (Aldoxorubicin and DK049), polymeric micelle (NC-6300), polymer conjugates (ProLindac™), and an immunoconjugate (IMMU-110). The article encompasses a broad spectrum of studies focused on the development of acid-sensitive prodrugs for anticancer, antibacterial, and anti-inflammatory agents. Finally, the challenges associated with the acid-sensitive prodrug strategy are discussed, along with future directions.

Targeted Anticancer Drug Delivery Using Chitosan, Carbon Quantum Dots, and Aptamers to Deliver Ganoderic Acid and 5-Fluorouracil

Breast cancer is a malignancy that affects mostly females and is among the most lethal types of cancer. The ligand-functionalized nanoparticles used in the nano-drug delivery system offer enormous potential for cancer treatments. This work devised a promising approach to increase drug loading efficacy and produce sustained release of 5-fluorouracil (5-FU) and Ganoderic acid (GA) as model drugs for breast cancer. Chitosan, aptamer, and carbon quantum dot (CS/Apt/COQ) hydrogels were initially synthesized as a pH-sensitive and biocompatible delivery system. Then, CS/Apt/COQ NPs loaded with 5-FU-GA were made using the W/O/W emulsification method. FT-IR, XRD, DLS, zeta potentiometer, and SEM were used to analyze NP's chemical structure, particle size, and shape. Cell viability was measured using MTT assays in vitro using the MCF-7 cell lines. Real-time PCR measured cell apoptotic gene expression. XRD and FT-IR investigations validated nanocarrier production and revealed their crystalline structure and molecular interactions. DLS showed that nanocarriers include NPs with an average size of 250.6 nm and PDI of 0.057. SEM showed their spherical form, and zeta potential studies showed an average surface charge of +37.8 mV. pH 5.4 had a highly effective and prolonged drug release profile, releasing virtually all 5-FU and GA in 48 h. Entrapment efficiency percentages for 5-FU and GA were 84.7±5.2 and 80.2 %±2.3, respectively. The 5-FU-GA-CS-CQD-Apt group induced the highest cell death, with just 57.9 % of the MCF-7 cells surviving following treatment. 5-FU and GA in CS-CQD-Apt enhanced apoptotic induction by flow cytometry. 5-FU-GA-CS-CQD-Apt also elevated Caspase 9 and downregulated Bcl2. Accordingly, the produced NPs may serve as pH-sensitive nano vehicles for the controlled release of 5-FU and GA in treating breast cancer.

Metal-organic frameworks (MOFs) as effectual diagnostic and therapeutic tools for cancer

Metal-organic frameworks (MOFs) are a class of multifunctional organometallic compounds that include metal ions combined with assorted organic linkers. Recently, these compounds have received widespread attention in medicine, due to their exceptional qualities, including a wide surface area, high porosity, outstanding biocompatibility, non-toxicity, etc. Such characteristic qualities make MOFs superb candidates for biosensing, molecular imaging, drug delivery, and enhanced cancer therapies. This review illustrates the key attributes of MOFs and their importance in cancer research. The structural and synthetic aspects of MOFs are briefly discussed with primary emphasis on diagnostic and therapeutic features, as well as their performance and significance in modern therapeutic methods and synergistic theranostic strategies including biocompatibility. This review offers cumulative scrutiny of the widespread appeal of MOFs in modern-day oncological research, which may stimulate further explorations.

Vitamin A-modified ZIF-8 lipid nanoparticles for the therapy of liver fibrosis

Liver fibrosis (LF) is one of the major diseases that threaten human health. Until now, no effective drugs have been approved for clinical anti-liver fibrosis treatment. In this study, zeolitic imidazolate framework-8 (ZIF-8) lipid nanoparticles loaded with pirfenidone (PFD) and modified with vitamin A (VA) were constructed (VA-PFD@ZIF-8@DMPC NPs). PFD was embedded in ZIF-8 by the "one-pot" method, and the prepared ZIF-8 had a small particle size (84.3 nm) and high drug loading (54.46%). Moreover, the inherent pH sensitivity of ZIF-8 makes it stable in a normal physiological environment and collapsed in an acidic environment, thus controlling drug release and preventing drug leakage. Besides, the phospholipid layer makes the nano-drug delivery system dispersible and improves its biocompatibility. More importantly, VA is modified on the surface of nanoparticles (NPs), which can target the highly expressed retinol-binding protein receptor (RBPR) on the surface of hepatic stellate cells (HSCs), thereby accurately increasing the local drug concentration at the site of LF. In vivo experiments showed that VA-PFD@ZIF-8@DMPC NPs can reduce liver injury, improve the degree of LF, and exert specific therapeutic effects on LF. In conclusion, this nano-delivery system may become a novel and effective anti-liver fibrosis treatment.

Synthesis and characterization of biological macromolecules double emulsion based on carboxymethylcellulose/gelatin hydrogel incorporated with ZIF-8 as metal organic frameworks for sustained anti-cancer drug release

The field of nanotechnology has introduced novel prospects for drug delivery systems, which have the potential to supplant conventional chemotherapy with reduced adverse effects. Despite being a promising porous material, ZIF-8, a metal-organic framework, tends to agglomerate in water, which limits its applicability. In order to resolve this problem, we added ZIF-8 to hydrogels consisting of gelatin and carboxymethylcellulose. This improved their mechanical strength and stability while avoiding aggregation. We utilized double emulsions with the hydrogels' biological macromolecules to construct drug carriers with enhanced control over drug release. The nanocarriers were subjected to various analytical techniques for characterization, such as Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), zeta potential, and dynamic light scattering (DLS). The findings of our study revealed that the mean size of the produced nanocarriers were 250 nm, and their zeta potential was -40.1 mV, which suggests favorable stability. The synthesized nanocarriers were found to exhibit cytotoxicity towards cancer cells, as evidenced by the results of MTT assays and flow cytometry tests. The cell viability percentage was determined to be 55 % for the prepared nanomedicine versus 70 % for the free drug. In summary, our study illustrates that the integration of ZIF-8 into hydrogels produces drug delivery systems with improved characteristics. Furthermore, the prepared nanocarriers exhibit potential for future investigation and advancement.

Fabrication of biocompatible magnetic maltose/MIL-88 metal-organic frameworks decorated with folic acid-chitosan for targeted and pH-responsive controlled release of doxorubicin

Recently, metal-organic frameworks (MOFs) have attracted tremendous attention as promising porous drug delivery systems for cancer treatment. In this work, for the first time, a novel magnetic maltose disaccharide molecule modified with MIL-88 metal-organic framework (Fe₃O₄@C@MIL-88) was prepared, and then this targeted system was used for the delivery of the doxorubicin (DOX) drug. Eventually, Fe₃O₄@C@MIL-88-DOX were successfully decorated with folic acid conjugated chitosan (Fe₃O₄@C@MIL-88-DOX-FC) as a new targeted and controlled release drug system for treatment of MCF-7 breast cancer. The encapsulation efficiency of the DOX in the Fe₃O₄@C@MIL-88 was obtained at ∼83.6%. The in vitro drug release profiles showed a pH-responsive controlled release of DOX in acidic pH confirming the performance of the systems in the cancerous environment. The DOX release mechanism from systems at pH 5 also showed that the kinetic data well fitted to the Korsmeyer-Peppas and Fickian diffusion. Furthermore, in vitro cytotoxicity and DAPI staining study clearly illustrated that the synthesized Fe₃O₄@C@MIL-88 system had low cytotoxicity and good biocompatibility against MCF-7 cancer cells and MCF-10A normal cells. Whereas, Fe₃O₄@C@MIL-88-DOX and Fe₃O₄@C@MIL-88-DOX-FC exhibited good antitumor activity as a result of targeted delivery of DOX, which indicated the MCF-7 cell death with apoptotic effects. Based on these findings, the resulting carriers could be used as promising targeted drug delivery systems for cancer therapy.

Preparation and application of pH-responsive drug delivery systems

Microenvironment-responsive drug delivery systems (DDSs) can achieve targeted drug delivery, reduce drug side effects and improve drug efficacies. Among them, pH-responsive DDSs have gained popularity since the pH in the diseased tissues such as cancer, bacterial infection and inflammation differs from a physiological pH of 7.4 and this difference could be harnessed for DDSs to release encapsulated drugs specifically to these diseased tissues. A variety of synthetic approaches have been developed to prepare pH-sensitive DDSs, including introduction of a variety of pH-sensitive chemical bonds or protonated/deprotonated chemical groups. A myriad of nano DDSs have been explored to be pH-responsive, including liposomes, micelles, hydrogels, dendritic macromolecules and organic-inorganic hybrid nanoparticles, and micron level microspheres. The prodrugs from drug-loaded pH-sensitive nano DDSs have been applied in research on anticancer therapy and diagnosis of cancer, inflammation, antibacterial infection, and neurological diseases. We have systematically summarized synthesis strategies of pH-stimulating DDSs, illustrated commonly used and recently developed nanocarriers for these DDSs and covered their potential in different biomedical applications, which may spark new ideas for the development and application of pH-sensitive nano DDSs.

Effectiveness of 5-Fluorouracil and gemcitabine hydrochloride loaded iron‑based chitosan-coated MIL-100 composite as an advanced, biocompatible, pH-sensitive and smart drug delivery system on breast cancer therapy

This study was planned to evolve the bioavailability and therapeutic efficiency of Gemcitabine (GEM) and 5-Fluorouracil with decreased side effects using MIL-100 nano-composite as carrier. Impregnation approach was used for encapsulation of 5-Fluorouracil alone and with GEM inside the MIL-100. The formed 5-Fluorouracil@MIL-100 and 5-Fluorouracil-GEM@MIL-100 were then coated with chitosan, sequentially chelated with iron(III) and conjugated with quercetin, eventually obtaining a multifunctional MIL-100 nanocarrier. The hybrid nanocarrier nascency was verified by different characterization results. pH-sensitive releases of 5-Fluorouracil and GEM were observed because of the inherent pH-dependent stability of MIL-100. Additionally, we evaluated the anti-cancer activity of these nanocarriers through WST-1 analysis and acridine orange staining in MCF-7 human breast cancer and HUVEC control cell lines. Our findings showed that all nanocarriers exhibited anti-cancer activity and induced apoptosis in MCF-7 cells. However, 5-Fluorouracil@MIL-100 and chitosan-coated 5-Fluorouracil@MIL-100 with quercetin were more effective than other nanocarriers in MCF-7 cells (p < 0.05). Moreover, we observed cytotoxicity in HUVEC cells due to the adverse side effects of chemotherapy drugs. However, chitosan coated nanocarriers with quercetin were less toxic on HUVEC cells at particularly 1 µg/mL. Therefore, MIL-100 could be used for a promising chemotherapeutic drugs delivery and chitosan coated drugs with quercetin could be useful for reducing toxicity on normal cells.

Fabrication of dopamine conjugated with protein @metal organic framework for targeted drug delivery: A biocompatible pH-Responsive nanocarrier for gemcitabine release on MCF‑7 human breast cancer cells

Metal-organic structures (MOF), modern extremely proliferous materials consisting of metal ions and organic coordinating molecules, has become a promising biomedical material because of its unusual features, including great surface area, wide pore volume, flexible functionality and superior performance for drug loading. In the current investigation, Gemcitabine Hydrochloride (Gem), an anticancer drug, and Amygdalin (Amy) were loaded into a nanocomposite structure formed from bovine serum albumin (BSA) as a center and zeolytic imidazolate framework-8 (ZIF-8) as a pH sensitive protective coating. The formed BSA-Gem@ZIF-8 and BSA-Gem-Amy@ZIF-8 were successively coated by polydopamine, chelated by Au³⁺ and conjugated via gallic acid (GA), acquired ZIF-8 structure as a multifunctional nanocarrier at the end. It was confirmed by different characterization methods that the nanocarrier was successfully produced. Due to the nature of ZIF-8, pH dependent releases of BSA-Gem@ZIF-8/Dopa/GA and BSA-Gem-Amy@ZIF-8/Dopa/GA were observed in in vitro studies. Cytotoxicity and apoptotic effects of these nanocarriers were evaluated using WST-1 and acridine orange staining in MCF-7 human breast cancer and HUVEC control cell lines. In-vitro cytotoxicity studies showed that both BSA-Gem@ZIF-8/Dopa/GA and BSA-Gem-Amy@ZIF-8/Dopa/GA were more effective than gemcitabine alone in MCF-7 cells with less toxicity in HUVEC cells. Additionally, both pH-responsive nanocarriers induced more apoptotic cell death in MCF-7 cells. We therefore believe that the built multifunctional nanocarrier based on ZIF-8 could be an alternative therapeutic strategy the use of gemcitabine for cancer therapy.

Synergistic antibacterial polyacrylonitrile/gelatin nanofibers coated with metal-organic frameworks for accelerating wound repair

Bacterial infections prolong the wound healing time and increase the suffering of patients, thus it is important to develop wound dressing that can inhibit bacterial infection. Herein, we use two methods including "doping method" and "secondary growth method" to prepare ZIF-8@gentamicin embedded in and coated on polyacrylonitrile/gelatin (PG) nanofibers, separately. Composite nanofibers prepared by the secondary growth method achieve higher drug loading than that of the doping method, and the release rate can be adjusted by pH. Simultaneously increasing drug loading and regulating its release rate are achieved in the secondary growth method, which cannot be achieved by the doping method. Furthermore, synergistic antibacterial property occurs in the composite nanofibers prepared by the secondary growth method, and gentamicin loaded on ZIF-8 promotes the antibacterial effect, which shows better antibacterial effect than the doping method. As a result, during the wound infection of mouse, composite nanofibers prepared by the secondary growth method exhibit a faster recovery effect than the doping method, which effectively shortened the wound healing time from 21 days to 16 days.