Fabrication and Use of Poly(d,l-lactide-co-glycolide)-Based Formulations Designed for Modified Release of 5-Fluorouracil

A Coarse-Grained Molecular Dynamics Perspective on the Release of 5-Fluorouracil from Liposomes

Liposomes, small bilayer phospholipid-containing vesicles, are frequently used to ensure slow drug release for a prolonged and improved therapeutic effect. Nevertheless, current findings on the membrane affinity and permeability of the anticancer agent 5-fluorouracil (5-FU) are confounding, which leads to a lack of a clear understanding of how lipid composition impacts the distribution of 5-FU within liposomal structures and its delivery. In the current work, we report a comprehensive coarse-grained molecular dynamics (CGMD) investigation on the influence of cholesterol (CHOL) and the cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) on the partitioning of 5-FU in 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) double-bilayer systems, as well as its in vitro release from liposomes with identical lipid compositions. Our results show that 5-FU tends to accumulate at the water-lipid interface, in the vicinity of polar headgroups, without partitioning in the hydrophobic tail region. At the same time, the presence of CHOL proportionally increases the distribution of this drug in the interbilayer aqueous space, decreasing the drug's affinity toward the membrane polar head region, while DOTAP has only a slight effect on drug distribution. Thus, it is expected that 5-FU will be released slower from CHOL-containing DPPC liposomes but not DOTAP-containing vesicles. However, in vitro release studies showed that the release kinetics of 5-FU from DPPC vesicles is not influenced by the presence of CHOL and that the incorporation of 10 mol % DOTAP leads to the best release profile for 5-FU, highlighting the complexity of nanocarrier drug release kinetics. We hypothesize that the initial rapid release seen in dialysis experiments is not related to drug membrane permeability but rather to 5-FU adsorbed on the outer surface of liposomes.

A thermoresponsive chitosan-based in situ gel formulation incorporated with 5-FU loaded nanoerythrosomes for fibrosarcoma local chemotherapy

Local administration of drugs at tumor sites over an extended period of time shows potential as a promising approach for cancer treatment. In the present study, the temperature-induced phase transition of chitosan and poloxamer 407 is used to construct an injectable hydrogel encapsulating 5-FU-loaded nanoerythrosome (5-FU-NER-gel). The 5-FU-NERs were found to be spherical, measuring approximately 115 ± 20 nm in diameter and having a surface potential of -7.06 ± 0.4. The drug loading efficiency was approximately 40 %. In situ gel formation took place within 15 s when the gel was exposed to body temperature or subcutaneous injection. A sustained release profile was observed at pH 7.4 and 6.8, with a total 5-FU release of 76.57 ± 4.4 and 98.07 ± 6.31 in 24 h, respectively. MTT, Live/dead, and migration assays confirmed the cytocompatibility of the drug carrier and its effectiveness as a chemotherapeutic formulation. After in vivo antitumor assessment in a subcutaneous autograft model, it was demonstrated that tumor growth inhibition in 14 days was 90 %. Therefore, the obtained injectable chitosan-based hydrogel containing 5-FU-loaded nanoerythrosomes illustrated promising potential as a candidate for local and enhanced delivery of chemotherapeutics at the tumor site.

A pH-responsive bi-MIL-88B MOF coated with folic acid-conjugated chitosan as a promising nanocarrier for targeted drug delivery of 5-Fluorouracil

Cancer has remained one of the leading causes of death worldwide, with a lack of effective treatment. The intrinsic shortcomings of conventional therapeutics regarding tumor specificity and non-specific toxicity prompt us to look for alternative therapeutics to mitigate these limitations. In this regard, we developed multifunctional bimetallic (FeCo) bi-MIL-88B-FC MOFs modified with folic acid-conjugated chitosan (FC) as drug delivery systems (DDS) for targeted delivery of 5-Fluorouracil (5-FU). The bi-MIL-88B nanocarriers were characterized through various techniques, including powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray, thermogravimetric analysis, and Fourier transform infrared spectroscopy. Interestingly, 5-FU@bi-MIL-88B-FC showed slower release of 5-FU due to a gated effect phenomenon endowed by FC surface coating compared to un-modified 5-FU@bi-MIL-88B. The pH-responsive drug release was observed, with 58% of the loaded 5-FU released in cancer cells mimicking pH (5.2) compared to only 24.9% released under physiological pH (5.4). The in vitro cytotoxicity and cellular internalization experiments revealed the superiority of 5-FU@bi-MIL-88B-FC as a highly potent targeted DDS against folate receptor (FR) positive SW480 cancer cells. Moreover, due to the presence of Fe and Co in the structure, bi-MIL-88B exhibited peroxidase-like activity for chemodynamic therapy. Based on the results, 5-FU@bi-MIL-88B-FC could serve as promising candidate for smart DDS by sustained drug release and selective targeting.

Development and cytotoxicity evaluation of multiple nanoemulsions for oral co-delivery of 5-fluorouracil and short chain triglycerides for colorectal cancer

Colorectal cancer (CRC) is the third most common cancer in the world, but current chemotherapy options are limited due to adverse effects and low oral bioavailability of drugs. In this study, we investigated the obtainment parameters and composition of new multiple nanoemulsions (MN) based on microemulsions for oral co-delivery of 5-fluorouracil (5FU) and short-chain triglycerides (SCT, either tributyrin or tripropionin). The area of microemulsion formation was increased from 14% to 38% when monocaprylin was mixed with tricaprylin as oil phase. Addition of SCT reduced this value to 24-26%. Using sodium alginate aqueous dispersion as internal aqueous phase (to avoid phase inversion) did not further affected the area but increased microemulsion viscosity by 1.5-fold. To obtain the MN, selected microemulsions were diluted in an external aqueous phase; droplet size was 500 nm and stability improved using polyoxyethylene (den Besten et al., 2013) oleyl ether at 1-2.5% as surfactant in the external phase and a dilution ratio of 1:1 (v/v). 5FU in vitro release could be better described by the Korsmeyer-Peppas model. No pronounced changes in droplet size were observed when selected MNs were incubated in buffers mimicking gastrointestinal fluids. The 5FU cytotoxicity in monolayer cell lines presenting various mutations was influenced by its incorporation in the nanocarrier, presence of SCT and cell mutation status. The MNs selected reduced the viability of tumor spheroids (employed as 3D tumor models) by 2.2-fold compared to 5FU solution and did not affect the survival of the G. mellonella, suggesting effectiveness and safety.

Programmable Drug Release from a Dual-Stimuli Responsive Magnetic Metal-Organic Framework

Along with the increasing incidence of cancer and drawbacks of traditional drug delivery systems (DDSs), developing novel nanocarriers for sustained targeted-drug release has become urgent. In this regard, metal-organic frameworks (MOFs) have emerged as potential candidates due to their structural flexibility, defined porosity, lower toxicity, and biodegradability. Herein, a FeMn-based ferromagnetic MOF was synthesized from a preassembled Fe₂Mn(μ₃-O) cluster. The introduction of the Mn provided the ferromagnetic character to FeMn-MIL-88B. 5-Fluoruracil (5-FU) was encapsulated as a model drug in the MOFs, and its pH and H₂S dual-stimuli responsive controlled release was realized. FeMn-MIL-88B presented a higher 5-FU loading capacity of 43.8 wt % and rapid drug release behavior in a tumor microenvironment (TME) simulated medium. The carriers can rapidly release loaded drug of 70% and 26% in PBS solution (pH = 5.4) and NaHS solution (500 μM) within 24 h. The application of mathematical release models indicated 5-FU release from carriers can be precisely fitted to the first-order, second-order, and Higuchi models of release. Moreover, the cytotoxicity profile of the carrier against human embryonic kidney cells (HEK293T) suggests no adverse effects up to 100 μg/mL. The lesser toxic effect on cell viability can be attributed to the low toxicity values [LD₅₀ (Fe) = 30 g·kg^-1, (Mn) = 1.5 g·kg^-1, and (terephthalic acid) = 5 g·kg^-1] of the MOFs structural components. Together with dual-stimuli responsiveness, ferromagnetic nature, and low toxicity, FeMn-MIL-88B MOFs can emerge as promising carriers for drug delivery applications.

Changing the daily injection of glatiramer acetate to a monthly long acting product through designing polyester-based polymeric microspheres

Introduction: Glatiramer acetate (GA) is a newly emerged therapeutic peptide to reduce the frequency of relapses in multiple sclerosis (MS). Despite its good performance in controlling MS, it is not widely used due to daily or biweekly subcutaneous injections due to rapid degradation and body clearance. Therefore, implant design with sustained release leads to prolonged biological effects by gradually increasing drug exposure and protecting GA from rapid local degradation. Methods: Different emulsion methods, PLGA type, surfactant concentration, drug/polymer ratio, drying processes, stirring method, and other variables in preliminary studies modified the final formulation. The release kinetics were studied through mechanistic kinetic models such as zero-order, Weibull, Higuchi, etc. In this study, all challenges for easy scale-up, methodological detail, and a simple, feasible setup in mass production were discussed. Results: The optimized formulation was obtained by 1:6 drug/PLGA, 0.5% w/w polyvinyl alcohol, and 0.75% w/w NaCl in the external aqueous phase, 1:10 continuous phase to dispersed phase ratio, and without any surfactant in the primary emulsion. The final freeze-dried particles presented a narrow distributed size of 1-10 µm with 7.29% ± 0.51 drug loading and zero-order release behavior with appropriate regression correlation (R2 98.7), complete release, and only 7.1% initial burst release. Conclusion: Therefore, to achieve improvement in patient compliance through better and longer efficacy, designing the parenteral sustained release microspheres (MPSs) of this immune modulator is a promising approach that should be considered.

Thermosensitive Interfacial Migration of 5-FU in the Microenvironment of Pluronic Block Copolymers

Chemotherapy is one of the most important ways to treat cancer. At present, chemotherapy medicines are mainly administered by intravenous injection or oral administration. However, systemic medical care requires the dosage of high concentrations of drugs to defeat the malignant tumor growth. In recent years, the use of polymer composites for local and sustained drug release has become an important field of research to minimize side effects due to high-concentration chemotherapy drugs. Here, ¹⁹F-{¹H} heteronuclear Overhauser enhancement spectroscopy (HOESY) was used to study the micellular environment of the F-containing chemotherapeutic drug 5-FU in Pluronic F127, Pluronic L121, and F127/L121 binary blending composites. The distribution of 5-FU in micelles is related to the PEO and PPO segment length of Pluronic polymers and the environmental temperature. The drug release tests further confirm that if 5-FU medicines were loaded in the PPO segment inside the micelles, the purpose of the prolonged drug release carrier is achieved.

Is it possible to repigment iatrogenic and traumatic hypochromic lesions? A case series using the MMP® drug delivery technique with 5-fluorouracil and bleomycin

OBJECTIVES

We present the results of 11 patients with hypochromic lesions treated with antifibrotic agents delivered through the MMP^® technique.

METHODS

Eleven patients with hypochromic lesions because of external injuries were treated at a single clinic with 5-fluorouracil (5-FU) and/or bleomycin using the MMP^® drug delivery technique. Treatment sessions were repeated at 30-day intervals until patient satisfaction. The primary outcome was repigmentation of the lesions, assessed independently by two dermatologists and by the patient.

RESULTS

The MMP^® technique injected 0.048 mg/cm² of 5-FU or 0.0028 U/cm² of bleomycin. The accumulated 5-FU and bleomycin density per patient ranged from 0.02 to 0.77 mg and 0.0022 to 0.2800 U/ml, respectively. Patients were treated with 1 to 6 MMP^® sessions with 5-FU (3 patients), bleomycin (6 patients), or both drugs (2 patients). After the last session, all patients had a significant improvement (>75%) of the lesions compared to baseline. There were no procedure-related short- or long-term adverse effects in any of the participants up to their last follow-up visit.

CONCLUSIONS

The injection of antifibrotic agents using the MMP^® technique was effective and safe in the treatment of hypochromic lesions. This can be a new therapeutic option for these lesions.

Tetraspanins: Novel Molecular Regulators of Gastric Cancer

Gastric cancer is the fourth and fifth most common cancer worldwide in men and women, respectively. However, patients with an advanced stage of gastric cancer still have a poor prognosis and low overall survival rate. The tetraspanins belong to a protein superfamily with four hydrophobic transmembrane domains and 33 mammalian tetraspanins are ubiquitously distributed in various cells and tissues. They interact with other membrane proteins to form tetraspanin-enriched microdomains and serve a variety of functions including cell adhesion, invasion, motility, cell fusion, virus infection, and signal transduction. In this review, we summarize multiple utilities of tetraspanins in the progression of gastric cancer and the underlying molecular mechanisms. In general, the expression of TSPAN8, CD151, TSPAN1, and TSPAN4 is increased in gastric cancer tissues and enhance the proliferation and invasion of gastric cancer cells, while CD81, CD82, TSPAN5, TSPAN9, and TSPAN21 are downregulated and suppress gastric cancer cell growth. In terms of cell motility regulation, CD9, CD63 and CD82 are metastasis suppressors and the expression level is inversely associated with lymph node metastasis. We also review the clinicopathological significance of tetraspanins in gastric cancer including therapeutic targets, the development of drug resistance and prognosis prediction. Finally, we discuss the potential clinical value and current limitations of tetraspanins in gastric cancer treatments, and provide some guidance for future research.

Multiple strategies with the synergistic approach for addressing colorectal cancer

Cancer treatment is improving widely over time, but finding a proper defender to beat them seems like a distant dream. The quest for identification and discovery of drugs with an effective action is still a vital work. The role of a membrane protein called P-glycoprotein, which functions as garbage chute that efflux the waste, xenobiotics, and toxins out of the cancer cells acts as a major reason behind the therapeutic failure of most chemotherapeutic drugs. In this review, we mainly focused on a multiple strategies by employing 5-Fluorouracil, curcumin, and lipids in Nano formulation for the possible treatment of colorectal cancer and its metastasis. Eventually, multidrug resistance and angiogenesis can be altered and it would be helpful in colorectal cancer targeting.We have depicted the possible way for the depletion of colorectal cancer cells without disturbing the normal cells. The concept of focusing on multiple pathways for marking the colorectal cancer cells could help in activating one among the pathways if the other one fails. The activity of the 5-Fluorouracil can be enhanced with the help of curcumin which acts as a chemosensitizer, chemotherapeutic agent, and even for altering the resistance. As we eat to survive, so do the cancer cells. The cancer cells utilize the energy source to stay alive and survive. Fatty acids can be used as the energy source and this concept can be employed for targeting the colorectal cancer cells and also for altering the resistant part.

JAK2/STAT3 inhibitor reduced 5-FU resistance and autophagy through ATF6-mediated ER stress

Drug resistance seriously limits the efficacy of chemotherapy drugs and hinders successful treatment in patients with gastric cancer. Endoplasmic reticulum (ER) and autophagy are recognized to be one of the mechanisms involving the drug resistance of gastric cancer. The mechanisms of action of JAK2/STAT3 pathway were investigated in AGS cells with drug resistance of 5-fluorouracil (5-FU) by corresponding inhibitors. We firstly analyzed the effects of JAK2/STAT3 inhibitor on the expression of drug resistance genes, autophagy markers, and ER stress-related markers on AGS/5-FU cells by Western blot. Whether JAK2/STAT3 pathway regulated the transcription of ATF6 was investigated through luciferase reporter assay. The expression of LC3B was detected by immunofluorescence assay. Next, ER stress inhibitor and ATF6 overexpression plasmid were respectively used to treat AGS/5-FU cells for analyzing whether JAK2/STAT3 pathway regulated ER stress. The results showed that JAK2 inhibitor or STAT3 inhibitor significantly altered the expression of these proteins and suppressed the activities of ATF6 promoter. Intriguingly, ATP6 overexpression could markedly reverse their effects. Moreover, similar effects to JAK2 inhibitor or STAT3 inhibitor appeared in ER stress inhibitor-treated group. These findings indicated that the involvement of JAK2/STAT3 pathway in regulating ER stress affected the 5-FU resistance of AGS cells and autophagy, which was mediated by ATF6. Targeting JAK2/STAT3 pathway could be a potential approach to decrease the 5-FU resistance of gastric cancer and enhance the sensitivity of gastric cancer to 5-FU. Additionally, our study offers new insights into the molecular mechanisms underlying the resistance of gastric cancer to 5-FU.

Pluronic-Coated Biogenic Gold Nanoparticles for Colon Delivery of 5-Fluorouracil: In vitro and Ex vivo Studies

The aim of the study was to prepare 5-fluorouracil (5-FU)-loaded biogenic gold nanoparticles with pluronic-based coating (PFGNPs), their optimization (full factorial predicted OBPN-1) and in vitro-ex vivo evaluation. Several formulations were prepared, selected for optimization using Design Expert®, and compared for morphology, 5-FU release kinetics, compatibility, cell line toxicity, in vitro hemocompatibility, and ex vivo intestinal permeation across the rat duodenum, jejunum, and ileum. The pluronic-coated 5-FU-carrying GNPs were spherical, 29.11-178.21 nm in diameter, with a polydispersity index (PDI) range of 0.191-292, and a zeta potential (ZP) range of 11.19-29.21 (-mV). The optimized OBPN-1 (desirability = 0.95) demonstrated optimum size (175.1 nm), %DL as 73.8%, ZP as 21.7 mV, % drug release (DR) as 75.7%, and greater cytotoxicity (viability ~ 8.9%) against the colon cancer cell lines than 5-FU solution (~ 24.91%), and less hemocompatibility. Moreover, OBPN-1 exhibited 4.5-fold permeation across the rat jejunum compared with 5-FU solution. Thus, the PFGNPs exhibit high DL capacity, sustained delivery, hemocompatibility, improved efficacy, and enhanced permeation profiles compared with 5-FU solution and several other NPs preparations suggesting it is a promising formulation for effective colon cancer control with reduced side effects.

Improved pharmacokinetic and biodistribution of 5-fluorouracil loaded biomimetic nanoerythrocytes decorated nanocarriers for liver cancer treatment

Nanoerythrocytes membrane (NEs) has recently been used to improve pharmacokinetics and biodistribution for successful drug therapy. NEs intended to enhance the drug targeting due to immune evasion and long circulation. In this work, NEs could serve as efficient 5- fluorouracil (5-FU) carriers to target liver cells. NEs decorated 5-FU-loaded chitosan coated-poly (lactide-co-glycolic acid) nanoparticles (5-FU-C-NPs-NEs), chitosomes (5-FU-C-LPs-NEs) and 5-FU-NEs were prepared by hypotonic lysis and extrusion procedures. Moreover, 5-FU loaded-chitosan coated 5-FU-NPs (5-FU-C-NPs) and chitosomes (5-FU-C-LPs) for the compared issues were prepared. They were characterized in terms of particle size, encapsulation efficiency (EE), membrane protein content, phosphatidylserine exposure, surface morphology, and in vitro release profiles. Also, their cytotoxic efficacy was determined. Furthermore, pharmacokinetics and biodistribution studies were investigated for optimized formulation. The results revealed that 5-FU-C-NPs-NEs have narrow particle size distribution, desirable EE%, and retained the erythrocyte membrane properties as confirmed by polyacrylamide gel electrophoresis (SDS-PAGE). Additionally, it displayed a sustained release profile up to 72 h of 5-FU-C-NPs-NEs compared to other formulations. In comparison to 5-FU solution and 5-FU-C-NPs, 5-FU-C-NPs-NEs extended the drug release time in vivo with highly uptake by the liver. These results suggest that the 5-FU-C-NPs-NEs could be used to deliver 5-FU and enhance its targetability to liver cancer.

Breast Tumor Targeting with PAMAM-PEG-5FU-99mTc As a New Therapeutic Nanocomplex: In In-vitro and In-vivo studies

Dendrimer-based targeted drug delivery, as an innovative polymeric drug-delivery system, is promising for cancer therapy. Folate receptors (FR) are overexpressed in many types of tumor cells, such as breast cell carcinomas, which allow folate-targeted delivery. Therefor polyethylene glycol (PEG) modified-PAMAM G4 dendrimers were functionalized with folic acid (FA), as targeting agent. Then, 5-FU (5-fluorouracil) and ^99mTc (technetium-99 m) as therapeutic agents were respectively loaded and conjugated to previous nano-complex (PEG-PAMAM G4-FA-5FU-^99mTc). The value of drug loading was calculated by TGA analysis (16.97%). Drug release profiles of PEG-PAMAM G4-FA-5FU-^99mTc and PEG-PAMAM G4-FA-5FU were evaluated. The radiochemical purity of PEG-PAMAM G4-FA-5FU-^99mTc and PEG-PAMAM G4-FA-^99mTc was obtained at >95% with excellent in-vitro and in-vivo stabilities. PEG-PAMAM G4-FA-5FU-^99mTc was synthesized and the stability studies were carried out by the ITLC methods in serum (86.67% and 83.75%) and PBS. Combinational therapy effects of 5-FU and ^99mTc containing nano-complexes were evaluated on 4 T1 (mouse breast cancer) and MDA-MB-231 (human breast adenocarcinoma) cancer cell lines. Excellent uptake values were obtained for FA-decorated nano-complexes on 4 T1 and MDA-MB-231 cell lines. Subsequently, tumor inhibition effects of PEG-PAMAM G4-FA-5FU-^99mTc and PEG-PAMAM G4-FA-5FU were evaluated using the breast tumor-bearing BALB/C mice. Graphical abstract Breast Tumor Targeting with PAMAM-PEG-5FU- ^99mTc As a New Therapeutic Nanocomplex: in In-vitro and In-vivo Studies was presented. This targeted drug delivery system can significantly increase the efficiency of cancer therapy, and reduce the treatment cost and time.

Combined Therapeutic Effects of 131I-Labeled and 5Fu-Loaded Multifunctional Nanoparticles in Colorectal Cancer

Background

Owing to its combined effects, the co-delivery of different therapeutics is a promising option for the treatment of cancer. In the present study, tumor-targeting poly(ethylene glycol)-poly(lactic acid) (PEG-PLA) nanoparticles were developed for the transportation of two molecules, namely chemotherapeutic drug 5-fluorouracil (5Fu) and radionuclide iodine-131 (¹³¹I), in a single platform.

Methods

The obtained nanoparticles (Cetuximab [Cet]-PEG-PLA-5Fu-¹³¹I) were spherical (diameter approximately 110 nm) and pH-sensitive. The targeting effect of nanoparticles via Cet was confirmed in colorectal cancer cells using a fluorescent assay. The combined effects of Cet-PEG-PLA-5Fu-¹³¹I on cell viability and apoptosis were evaluated in colorectal cancer cells by Cell Counting Kit-8 and flow cytometry assays.

Results

Blank nanoparticles (Cet-PEG-PLA) showed good biocompatibility, and Cet-PEG-PLA-5Fu-¹³¹I nanoparticles were the most effective in terms of inhibition of cell viability and induction of apoptosis compared with monotherapy using Cet-PEG-PLA-5Fu or Cet-PEG-PLA-¹³¹I. In the xenograft mouse model, compared with using Cet-PEG-PLA-5Fu or Cet-PEG-PLA-¹³¹I alone, Cet-PEG-PLA-5Fu-¹³¹I nanoparticles exhibited prolonged circulation in the blood and accumulation in the tumor, thus resulting in enhanced antitumor efficacy. Additionally, combined radio-chemotherapy with Cet-PEG-PLA-5Fu-¹³¹I nanoparticles was associated with smaller tumor sizes than monotherapy, revealing the superior antitumor effects of Cet-PEG-PLA-5Fu-¹³¹I nanoparticles. These effects were further evidenced by histological and immunohistochemical analyses.

Conclusion

The multifunctional Cet-PEG-PLA-5Fu-¹³¹I nanoparticles are promising candidates for the co-delivery of 5Fu-mediated chemotherapy and ¹³¹I-mediated radiotherapy.

A Luminescent Mg-Metal-Organic Framework for Sustained Release of 5-Fluorouracil: Appropriate Host-Guest Interaction and Satisfied Acid-Base Resistance

It is important to achieve a moderate sustained release rate for drug delivery, so it is critical to regulate the host-guest interactions for the rational design of a carrier. In this work, a nano-sized biocompatible metal-organic framework (MOF), Mg(H₂TBAPy)(H₂O)₃·C₄H₈O₂ (TDL-Mg), was constructed by employing π-conjugated 1,3,6,8-tetrakis(p-benzoic acid)pyrene (H₄TBAPy) as a ligand and used for 5-fluorouracil (5-FU) loading (28.2 wt %) and sustained slow release. TDL-Mg exhibits a 3D supramolecular architecture featuring a 1D rectangle channel with a size of 6.2 × 8.1 Ų and a Brunauer-Emmett-Teller surface area of 627 m²·g^-1. Channel microenvironment analysis shows that the rigid H₂TBAPy^2- ligand adopts special torsion to stabilize the channels and offer rich π-binding sites; the partially deprotonated carboxyls not only participate in the formation of strong hydrogen bonds but also create a mild pH buffer environment for biological applications. Suitable host-guest interactions are generated by the synergistic effect of polydirectional hydrogen bonds, multiple π-interactions, and confined channels, which allow 5-FU@TDL-Mg to release 76% of load in 72 h, a medically reasonable rate. Microcalorimetry was used to directly quantify these host-guest interactions with a moderate enthalpy of 22.3 kJ·mol^-1, which provides a distinctive thermodynamic interpretation for understanding the relationship between the MOF design and the drug release rate. Additionally, the nano-sized 5-FU@TDL-Mg can be taken up by mouse breast cancer cells (4T1 cells) for imaging based on the dramatic fluorescence change during the release of 5-FU, exhibiting potential applications in biological systems.

Microfluidic-Assisted Preparation of 5-Fluorouracil-Loaded PLGA Nanoparticles as a Potential System for Colorectal Cancer Therapy

This work aims at fabricating 5-fluorouracil (5-FU)-loaded poly (lactic-co-glycolic) acid nanoparticles (PLGA NPs) using a microfluidic (MF) technique, with potential for use in colorectal cancer therapy. In order to achieve 5-FU-loaded NPs with an average diameter of approximately 119 nm, the parameters of MF process with fork-shaped patterns were adjusted as follows: the ratio of polymer to drug solutions flow rates was equal to 10 and the solution concentrations of PLGA as carrier, 5-FU as anti-cancer drug and poly (vinyl alcohol) (PVA) as surfactant were 0.2 (% w/v), 0.01 (% w/v) and 0.15 (% w/v), respectively. In this way, a drug encapsulation efficiency of approximately 95% into the PLGA NPs was obtained, due to the formation of a hydrodynamic flow focusing phenomenon through the MF chip. A performance evaluation of the NP samples in terms of the drug release, cytotoxicity and cell death was carried out. Finally, by analyzing the results after induction of cell death and 4', 6-diamidino-2-phenylin-dole (DAPI) staining, MF-fabricated NPs containing 5-FU [0.2 (% w/v) of PLGA] revealed the dead cell amounts of 10 and 1.5-fold higher than the control sample for Caco2 and SW-480, respectively.

Sulfasalazine Resolves Joint Stiffness in a Rabbit Model of Arthrofibrosis

Joint stiffness due to fibrosis/capsule contracture is a seriously disabling complication of articular injury that surgical interventions often fail to completely resolve. Fibrosis/contracture is associated with the abnormal persistence of myofibroblasts, which over-produce and contract collagen matrices. We hypothesized that intra-articular therapy with drugs targeting myofibroblast survival (sulfasalazine), or collagen production (β-aminopropionitrile and cis-hydroxyproline), would reduce joint stiffness in a rabbit model of fibrosis/contracture. Drugs were encapsulated in poly[lactic-co-glycolic] acid pellets and implanted in joints after fibrosis/contracture induction. Capsule α-smooth muscle actin (α-SMA) expression and intimal thickness were evaluated by immunohistochemistry and histomorphometry, respectively. Joint stiffness was quantified by flexion-extension testing. Drawer tests were employed to determine if the drugs induced cruciate ligament laxity. Joint capsule fibroblasts were tested in vitro for contractile activity and α-SMA expression. Stiffness in immobilized joints treated with blank pellets (control) was significantly higher than in non-immobilized, untreated joints (normal) (p = 0.0008), and higher than in immobilized joints treated with sulfasalazine (p = 0.0065). None of the drugs caused significant cruciate ligament laxity. Intimal thickness was significantly lower than control in the normal and sulfasalazine-treated groups (p = 0.010 and 0.025, respectively). Contractile activity in the cells from controls was significantly increased versus normal (p = 0.001). Sulfasalazine and β-aminopropionitrile significantly inhibited this effect (p = 0.005 and 0.0006, respectively). α-SMA expression was significantly higher in control versus normal (p = 0.0021) and versus sulfasalazine (p = 0.0007). These findings support the conclusion that sulfasalazine reduced stiffness by clearing myofibroblasts from fibrotic joints. Statement of clinical significance: The results provide proof-of-concept that established joint stiffness can be resolved non-surgically. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:629-638, 2020.

TSPAN9 suppresses the chemosensitivity of gastric cancer to 5-fluorouracil by promoting autophagy

Background

The issue of drug resistance in gastric cancer has attracted global attention. TSPAN9, a 4-transmembrane protein that plays an important role in tumor progression and signal transduction, has been found to be closely related to tumor invasion, metastasis, and autophagy.

Methods

Immunoblotting was used to evaluate TSPAN9 expression in parental and drug-resistant gastric cancer cells. Functional assays, such as the CCK-8 assay, were used to detect the proliferation of gastric cancer cells and the response of TSPAN9 to 5-fluorouracil (5-FU). Western blotting was used to analyze the expression of constituents of the PI3K/AKT/mTOR-mediated autophagy pathway induced by TSPAN9. Coimmunoprecipitation was performed to assess the specific mechanism by which TSPAN9 affects the PI3K pathway.

Results

We demonstrated that TSPAN9 is overexpressed in 5-FU-resistant cells compared to parental cells. 5-FU-mediated inhibition of cell proliferation can be significantly restored by increasing TSPAN9 expression, and inhibiting this expression in drug-resistant cells can restore the sensitivity of the cells to 5-FU. In addition, TSPAN9 also significantly promoted autophagy in gastric cancer cells in vitro. Further studies indicated that TSPAN9 downregulates the expression of PI3K and proteins associated with PI3K-mediated autophagy. In addition, TSPAN9 interacts with PI3K and inhibits its catalytic activity.

Conclusion

The current study reveals the important role of TSPAN9 in drug resistance to 5-FU in gastric cancer. It also provides a new target to clinically address drug-resistant gastric cancer and will contribute to the treatment strategy of this disease.

In-situ forming implants for the treatment of periodontal diseases: Simultaneous controlled release of an antiseptic and an anti-inflammatory drug

Different types of in-situ forming implants based on poly(lactic-co-glycolic acid) (PLGA) for the controlled dual release of an antiseptic drug (chlorhexidine) and an anti-inflammatory drug (ibuprofen) were prepared and thoroughly characterized in vitro. N-methyl-pyrrolidone (NMP) was used as water-miscible solvent, acetyltributyl citrate (ATBC) as plasticizer and hydroxypropyl methylcellulose (HPMC) was added to enhance the implants' stickiness/bioadhesion upon formation within the periodontal pocket. Different drug forms exhibiting substantially different solubilities were used: chlorhexidine dihydrochloride and digluconate as well as ibuprofen free acid and lysinate. The initial drug loadings were varied from 1.5 to 16.1%. In vitro drug release, dynamic changes in the pH of the surrounding bulk fluid and in the systems' wet mass as well as polymer degradation were monitored. Importantly, the release of both drugs, chlorhexidine and ibuprofen, could effectively be controlled simultaneously during several weeks. Interestingly, the tremendous differences in the drug forms' solubilities (e.g., factor >5000) did not translate into major differences in the resulting release kinetics. In the case of ibuprofen, this can likely (at least in part) be attributed to significant drug-polymer interactions (ibuprofen acts as a plasticizer for PLGA). In the case of chlorhexidine, the release of the much less soluble dihydrochloride was even faster compared to the more soluble digluconate (when combined with ibuprofen free acid). In the case of ibuprofen, at higher initial drug loadings also limited solubility effects within the implants seem to play a role, in contrast to chlorhexidine. In the latter case, instead, increased system porosity effects likely dominate at higher drug loadings.

Supramolecular Tripeptide Hydrogel Assembly with 5-Fluorouracil

In this work, we present Thioflavin T fluorescence, transmission electron microscopy (TEM), circular dichroism (CD), Fourier-transformed infrared (FT-IR), and oscillatory rheometry studies applied to an antineoplastic drug, 5-fluorouracil (5-FU), embedded in a heterochiral tripeptide hydrogel to obtain a drug delivery supramolecular system. The release of 5-fluorouracil was monitored over time by reverse-phase high-performance liquid chromatography (HPLC) and its interaction with the tripeptide assemblies was probed by all-atom molecular dynamics simulations.

Prognostic values of E2F mRNA expression in human gastric cancer

Gastric cancer (GC) is the second most frequent cause of cancer-related mortality in the world, with Eastern Asia having the highest incidence rates. E2F is a family of transcription factor proteins that has a variety of functions, which include control of cell cycle, cell differentiation, DNA damage response and cell death. E2F transcription factors are divided into two subfamilies: transcription activators (E2F transcription factors 1 (E2F1), 2 (E2F2) and 3a (E2F3a)) and repressors (E2F3b, E2F transcription factors 4 (E2F4), 5 (E2F5), 6 (E2F6), 7 (E2F7) and 8 (E2F8)). Studies have demonstrated that E2F had prognostic significance in a number of cancers. However, the entirety of the prognostic roles of E2F mRNA expression in GC has not yet been apparently determined. In the present study, the prognostic value of individual family members of E2F mRNA expression for overall survival (OS) was evaluated by using online Kaplan-Meier Plotter (KM Plotter) database. Our result demonstrated that high expressions of three family members of E2F (E2F1, E2F3, E2F4) mRNA were significantly associated with unfavourable OS in all GC patients. However, increased expressions of E2F2, E2F5, E2F6 and E2F7 were significantly associated with favourable OS, especially for higher clinical stages in GC patients. These results provided a better insight into the prognostic functions of E2F mRNA genes in GC. Although the results should be further verified in clinical trials, our findings may be a favourable prognostic predictor for the development of newer therapeutic drugs in the treatment of GC.