Reliable differentiation of necrosis and active metabolically contours of glioblastoma multiforme using susceptibility-based imaging

Purpose

Gadolinium-enhancing necrosis in glioblastoma multiforme (GBM), as an occasionally occurring false positive in contrast enhancement (CE) imaging, leads to trouble for segmentation of GBM and treatment. Therefore, the investigation of complementary detection way to identify the metabolically active volume of the tumor with high reliability is very worth to be addressed. Here, we reported on a case of GBM with gadolinium-enhancing necrosis in an experimental CE imaging study in mice and evaluated the discrimination of the necrosis and metabolically active parts of the GBM using conventional and state-of-the-art susceptibility-based MRI.

Methods

In this study, following 5-aminolevulinic acid (ALA) and iron supplements (FAC, 6 h after ALA, intra-tumoral injection) to animal, T2*-W imaging and quantitative susceptibility mapping (QSM) were performed, and compared with CE imaging.

Results

The signal intensity (SI) of the active and necrosis areas of the case in the CE image demonstrated no significant difference while the SI on the T2*-W images and susceptibility value in QSM changed 24 and 150%, respectively.

Conclusion

The preclinical case report provides valuable insights into the potential of susceptibility-based MRI using ALA + FAC to apply as a robust discriminator between necrotic and viable tumors.

NSF evaluation of gadolinium biodistribution in renally impaired rats: Using novel metabolic Gd2O3 nanoparticles coated with β-cyclodextrin (Gd2O3@PCD) in MR molecular imaging

The use of conventional gadolinium(Gd)-based contrast agents in magnetic resonance imaging (MRI) poses a significant risk of Nephrogenic Systemic Fibrosis (NSF) syndrome in patients with impaired renal function (grades 4 and 5). To address this issue, a new study has introduced a novel metabolic Gadolinium oxide nanoparticle (Gd2O3 NPs) coated with β-cyclodextrin (βCD). The study aims to investigate NSF syndrome by quantifying tissue Gd deposition biodistribution in renal impairment rats using MR molecular imaging. This is the first study of its kind to use this approach. A group of 20 rats were divided into four groups, each containing five rats that underwent 5/6 nephrectomy. The rats received 12 intravenous injections of a novel homemade synthesized gadolinium oxide polycyclodextrin (Gd2O3@PCD) at a dose of 0.1 mmol/kg, conventional contrast agents (CAs) drugs of Omniscan (Gd-DTPA-BMA) and Dotarem (Gd-DOTA), at a dose of 2.5 mmol/kg, and 250 μl saline for two injections per week during six weeks. T1-weighted MR imaging was performed before the injections and once a week for six weeks to quantify Gd deposition in four different organs (skin, liver, heart, and lung) in rats using inductively coupled plasma mass spectrometry (ICP-MS). The relationship between Signal-to-Noise Ratio (SNR) and biodistribution of Gd deposition due to NSF-induced syndrome was also calculated. The results of the study showed that the Gd concentrations in tissues were significantly higher in the Gd2O3@PCD group compared to the other groups, without any significant histopathological changes (P < 0.05). In the Gd2O3@PCD group, Gd was mainly deposited in the skin, followed by the liver, lung, and heart, without any symptoms of thickening or hardening of the skin. The Gd concentrations in the skin, liver, lung, and heart were significantly lower in the Dotarem group than in the Omniscan group (P < 0.05). In the histopathological examinations, the Omniscan group showed increased cellularity in the dermis. A significant hyperintensity was observed in the Gd2O3@PCD-treated rats compared to the Dotarem and Omniscan groups in the liver, heart, and lung. Compared to conventional Gd-based CAs, the novel metabolically Gd2O3@PCD with increased SNR, biosafety, and a considerably lower probability of developing NSF, has potential applicability for diagnosing patients with renal diseases in clinical MR Molecular Imaging (MRMI).

PEI-based functional materials: Fabrication techniques, properties, and biomedical applications

Cationic polymers have recently attracted considerable interest as research breakthroughs for various industrial and biomedical applications. They are particularly interesting due to their highly positive charges, acceptable physicochemical properties, and ability to undergo further modifications, making them attractive candidates for biomedical applications. Polyethyleneimines (PEIs), as the most extensively utilized polymers, are one of the valuable and prominent classes of polycations. Owing to their flexible polymeric chains, broad molecular weight (MW) distribution, and repetitive structural units, their customization for functional composites is more feasible. The specific beneficial attributes of PEIs could be introduced by purposeful functionalization or modification, long service life, biocompatibility, and distinct geometry. Therefore, PEIs have significant potential in biotechnology, medicine, and bioscience. In this review, we present the advances in PEI-based nanomaterials, their transfection efficiency, and their toxicity over the past few years. Furthermore, the potential and suitability of PEIs for various applications are highlighted and discussed in detail. This review aims to inspire readers to investigate innovative approaches for the design and development of next-generation PEI-based nanomaterials possessing cutting-edge functionalities and appealing characteristics.

Chondroitinase as a therapeutic enzyme: Prospects and challenges

The chondroitinases (Chase) are bacterial lyases that specifically digest chondroitin sulfate and/or dermatan sulfate glycosaminoglycans via a β-elimination reaction and generate unsaturated disaccharides. In recent decades, these enzymes have attracted the attention of many researchers due to their potential applications in various aspects of medicine from the treatment of spinal cord injury to use as an analytical tool. In spite of this diverse spectrum, the application of Chase is faced with several limitations and challenges such as thermal instability and lack of a suitable delivery system. In the current review, we address potential therapeutic applications of Chase with emphasis on the challenges ahead. Then, we summarize the latest achievements to overcome the problems by considering the studies carried out in the field of enzyme engineering, drug delivery, and combination-based therapy.

Signal amplification of a quartz crystal microbalance immunosensor by gold nanoparticles-polyethyleneimine for hepatitis B biomarker detection

The procedures currently used for hepatitis B (HB) detection are not suitable for screening, clinical diagnosis, and point-of-care testing (POCT). Therefore, we developed and tested a QCM-based immunosensor by surface modification with AuNP-PEIs to amplify the signal and provide an oriented-immobilization surface. The AuNP-PEIs were characterized by ICP-Mass, UV/Vis, DLS, FE-SEM, and ATR-FTIR. After coating AuNP-PEIs on the gold electrode surface, anti-HBsAg antibodies were immobilized using NHS/EDC chemistry based on response surface methodology (RSM) optimization. The efficiency of the immunosensor was assessed by human sera and data were compared to gold-standard ELISA using receiver-operating-characteristic (ROC) analysis. FE-SEM, AFM, EDS, and EDS mapping confirmed AuNP-PEIs are homogeneously distributed on the surface with a high density and purity. After antibody immobilization, the immunosensor exhibited good recognition of HBsAg with a calibration curve of ∆F =  - 6.910e-7x + 10(R2 = 0.9905), a LOD of 1.49 ng/mL, and a LOQ of 4.52 ng/mL. The immunosensor yielded reliable and accurate results with a specificity of 100% (95% CI 47.8-100.0) and sensitivity of 100% (95% CI 96.2-100.0). In conclusion, the fabricated immunosensor has the potential as an analytic tool with high sensitivity and specificity. However, further investigations are needed to convert it to a tiny lab-on-chip for HB diagnosis in clinical samples.

Alginate/gum arabic-based biomimetic hydrogel enriched with immobilized nerve growth factor and carnosine improves diabetic wound regeneration

Diabetic foot ulcers (DFUs) often remain untreated because they are difficult to heal, caused by reduced skin sensitivity and impaired blood vessel formation. In this study, we propose a novel approach to manage DFUs using a multifunctional hydrogel made from a combination of alginate and gum arabic. To enhance the healing properties of the hydrogel, we immobilized nerve growth factor (NGF), within specially designed mesoporous silica nanoparticles (MSN). The MSNs were then incorporated into the hydrogel along with carnosine (Car), which further improves the hydrogel's therapeutic properties. The hydrogel containing the immobilized NGF (SiNGF) could control the sustain release of NGF for >21 days, indicating that the target hydrogel (AG-Car/SiNGF) can serve as a suitable reservoir managing diabetic wound regeneration. In addition, Car was able to effectively reduce inflammation and significantly increase angiogenesis compared to the control group. Based on the histological results obtained from diabetic rats, the target hydrogel (AG-Car/SiNGF) reduced inflammation and improved re-epithelialization, angiogenesis, and collagen deposition. Specific staining also confirmed that AG-Car/SiNGF exhibited improved tissue neovascularization, transforming growth factor-beta (TGFβ) expression, and nerve neurofilament. Overall, our research suggests that this newly developed composite system holds promise as a potential treatment for non-healing diabetic wounds.

Catalase-gold nanoaggregates manipulate the tumor microenvironment and enhance the effect of low-dose radiation therapy by reducing hypoxia

Radiotherapy as a standard method for cancer treatment faces tumor recurrence and antitumoral unresponsiveness. Suppressive tumor microenvironment (TME) and hypoxia are significant challenges affecting efficacy of radiotherapy. Herein, a versatile method is introduced for the preparation of pH-sensitive catalase-gold cross-linked nanoaggregate (Au@CAT) having acceptable stability and selective activity in tumor microenvironment. Combining Au@CAT with low-dose radiotherapy enhanced radiotherapy effects via polarizing protumoral immune cells to the antitumoral landscape. This therapeutic approach also attenuated hypoxia, confirmed by downregulating hypoxia hallmarks, such as hypoxia-inducible factor α-subunits (HIF-α), vascular endothelial growth factor (VEGF), and EGF. Catalase stability against protease digestion was improved significantly in Au@CAT compared to the free catalase. Moreover, minimal toxicity of Au@CAT on normal cells and increased reactive oxygen species (ROS) were confirmed in vitro compared with radiotherapy. Using the nanoaggregates combined with radiotherapy led to a significant reduction of immunosuppressive infiltrating cells such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (T-regs) compared to the other groups. While, this combined therapy could significantly increase the frequency of CD8+ cells as well as M1 to M2 macrophages (MQs) ratio. The combination therapy also reduced the tumor size and increased survival rate in mice models of colorectal cancer (CRC). Our results indicate that this innovative nanocomposite could be an excellent system for catalase delivery, manipulating the TME and providing a potential therapeutic strategy for treating CRC.

In Situ Cross-Linkable Hyaluronic-Ferulic Acid Conjugate Containing Bucladesine Nanoparticles Promotes Neural Regeneration after Spinal Cord Injury

Dysfunctional clinical outcomes following spinal cord injury (SCI) result from glial scar formation, leading to the inhibition of new axon growth and impaired regeneration. Nevertheless, nerve regeneration after SCI is possible, provided that the state of neuron development in the injured environment is improved. Hence, biomaterial-based therapy would be a promising strategy to endow a desirable environment for tissue repair. Herein, we designed a novel multifunctional injectable hydrogel with antioxidant, neuroprotective, and neuroregenerative effects. Bucladesine-encapsulated chitosan nanoparticles (BCS NPs) were first prepared and embedded in a matrix of thiol-functionalized hyaluronic acid modified with ferulic acid (HASH-FA). The target hydrogel (HSP-F/BCS) was then created through Michael-type addition between HASH-FA containing BCS NPs and four-arm polyethylene glycol-maleimide (4-Arm-PEG-Mal). The obtained hydrogel with shear thinning behavior showed viscoelastic and mechanical properties similar to the normal nerve tissue. FA conjugation significantly improved the antioxidant activity of HA, and suppressed intracellular ROS formation. In situ injection of the HSP-F/BCS hydrogel in a rat contusion model of SCI inhibited glial scar progression, reduced microglia/macrophage infiltration, promoted angiogenesis, and induced myelinated axon regeneration. As a result, a significant improvement in motor performance was observed compared to other experimental groups. Taken together, the HSP-F/BCS hydrogel developed in this study could be a promising system for SCI repair.

Tannic acid-mediated synthesis of flower-like mesoporous MnO2 nanostructures as T1-T2 dual-modal MRI contrast agents and dual-enzyme mimetic agents

This study introduces a simple method for preparing a new generation of MnO2 nanomaterials (MNMs) using tannic acid as a template. Two shapes of MnO2 NMs, flower-like M1-MnO2 and near-spherical M2-MnO2, were prepared and compared as dual-active nanozymes and contrast agents in magnetic resonance imaging (MRI). Various parameters, including the crystallinity, morphology, magnetic saturation (Ms), surface functionality, surface area, and porosity of the MNMs were investigated. Flower-like M1-MnO2 NMs were biocompatible and exhibited pH-sensitive oxidase and peroxidase mimetic activity, more potent than near-spherical M2-MnO2. Furthermore, the signal intensity and r1 relaxivity strongly depended on the crystallinity, morphology, pore size, and specific surface area of the synthesized MNMs. Our findings suggest that flower-like M1-MnO2 NM with acceptable dual-enzyme mimetic (oxidase-like and peroxidase-like) and T1 MRI contrast activities could be employed as a promising theranostic system for future purposes.

Efficacy of Synthesized Cubic Spirulina Platensis Photosensitizer in Anticancer Photodynamic Therapy: An in vitro study

Photodynamic therapy (PDT) is becoming increasingly popular in cancer management. Photosensitizers derived from natural sources can offer additional health benefits and play a crucial role in enhancing the efficacy of PDT in cancer treatment. We herein synthesized a cubic form of spirulina platensis (SP) and compared its anticancer-PDT efficacy with the naturally-occurring microhelical SP (MSP) and phycocyanin (Pc) against a tongue cancer cell-line and fibroblast cells. Cubic SP (CSP) was synthesized and characterized using standard analyses. CAL-27 and HGF cell-lines were incubated at different concentrations with each photosensitizer and were irradiated with 635 nm diode-laser. The viability, cellular-uptake, apoptosis and oxidative stress potential were quantitatively analyzed and statistically compared at P<0.05. Our results demonstrated that all three photosensitizers were non-toxic to normal cells before laser irradiation. In CAL-27, viability significantly decreased after PDT in all photosensitizer groups (P<0.05). Whereas, in HGF, Pc exhibited phototoxicity after laser irradiation (P=0.032). Cell-death was mainly apoptotic in Pc and CSP, but necrotic in MSP. Cellular-uptake was significantly higher in Pc, but was similar in MSP and CSP. Increase in reactive oxygen species was significantly higher in the Pc group compared to both SPs (P<0.05). We concluded that both SPs were safe and efficient photosensitizers for anticancer-PDT. CSP exhibited predominant and significant apoptotic death in CAL-27 and HGF cell-lines, while MSP mainly induced necrotic cell death. Despite the good photosensitizing performance of Pc, its use in higher concentrations should be considered with caution, due to the reduced viability that occurred following its use in PDT.

A quartz crystal microbalance biosensor based on polyethylenimine-modified gold electrode to detect hepatitis B biomarker

Biomarkers-based QCM-biosensors are suitable tools for the label-free detection of infectious diseases. In the current study, a QCM-biosensor was developed for the detection of HBsAg. Briefly, anti-HBsAg antibodies were covalently bound to the primary amines after PEI and thiolated-PEI surface modifications of gold-electrode. After RSM optimization, the statistical analysis revealed no significant difference between the immobilization yields of modified layers. Therefore, the PEI-modified QCM-biosensor was selected for further analysis. The PEI-surface was evaluated by FESEM, AFM, ATR-FTIR, and CA measurement. The surface hydrophilicity and its roughness were increased after PEI-coating. Also, FTIR confirmed the PEI-layering on the gold-surface. RSM optimization increased the antibody immobilization yield up to 80%. The QCM-biosensor showed noteworthy results with a wide dynamic range of 1-1 × 10³ ng/mL, LOD of 3.14 ng/mL, LOQ of 9.52 ng/mL, and detection capability in human-sera, which were comparable with the ELISA. The mean accuracy of the QCM-biosensor was obtained at 91% when measured by the spike recovery test using human-sera. The biosensor was completely regenerated using 50 mM NaOH and 1% SDS. The benefits provided by the developed biosensor such as broad dynamic range, sensitivity, selectivity, stability, regenerate ability, and low cost suggest its potential application for the non-invasive and timely monitoring of HBV-biomarker.

A dual responsive robust human serum albumin-based nanocarrier for doxorubicin

Targeted drug therapy against cancer has been introduced as a smart strategy to combat the unwanted side effects due to systemic administration of chemotherapeutics. A human serum albumin (HSA)-based nanocarrier was fabricated with the aim to target reductive media and acidic pH of the tumor tissues. α-Lipoic acid (LA) was applied to increase the number of disulfide bonds in the nanocarrier to target higher glutathione concentrations present in tumor tissues and polyethylene glycol was used to target the acidic pH of tumors. UV illumination, ethanol desolvation, oxygen bubbling, and a mixture of redox buffers were employed to prepare doxorubicin-loaded HSA-LA nanoparticles. The nanocarrier was supposed to release the loaded doxorubicin in reductive and acidic pH media. Fourier-transform infrared spectroscopy and energy dispersive X-ray analysis indicated successful attachment of LA to HSA. The prepared nanoplatform presented improved doxorubicin loading efficiency and content and successfully released the loaded doxorubicin in the expected conditions. Protein corona study indicated that positively charged plasma proteins with molecular weights of nearly 80 kDa are absorbed to the surface of the nanoparticles. Furthermore, it showed desirable UV and storage stability, which implied its robustness and improved shelf life if applied in nanomedicine.

FruHis significantly increases the anti-benign prostatic hyperplasia effect of lycopene: A double-blinded randomized controlled clinical trial

BACKGROUND

For decades, lycopene was considered the main compound of tomato protecting benign prostatic hyperplasia (BPH). Recent animal studies suggest that a newly discovered compound "FruHis" boosts lycopene for its action. This study aimed to determine whether FruHis enhances the action of lycopene to modify the laboratory parameters and clinical outcomes of patients with BPH.

MATERIALS AND METHODS

Current study was conducted on 52 BPH patients, who were randomly assigned into four groups of treatments: lycopene plus FruHis (n = 11, 25 mg/day lycopene and 10 mg/day FruHis), lycopene (n = 12, 25 mg/day lycopene), FruHis (n = 12, 10 mg/day FruHis), and placebo (n = 13). Patients received these supplements for 8 weeks.

RESULTS

FruHis intake strengthened the reducing effects of lycopene on insulin-like growth factor-1 (IGF-1) (-54.47 ± 28.36 ng/mL in the lycopene + FruHis group vs. -30.24 ± 46.69 ng/mL in the lycopene group), total prostate-specific antigen (TPSA) (-1.49 ± 4.78 ng/mL in the lycopene + FruHis group vs. -0.64 ± 2.02 ng/mL in the lycopene group), and symptom score (-4.45 ± 4.03 in the lycopene + FruHis group vs. -1.66 ± 5.41 in the lycopene group) in BPH patients. Such findings were also seen for body mass index (BMI) and waist circumference (WC). However, except for IGF-1, these reductions were not statistically significant compared with the placebo, and the intakes of lycopene and FruHis alone, however, were clinically important. Such effects of lycopene and FruHis were not seen for free PSA (FPSA) and FPSA/TPSA ratio.

CONCLUSION

Despite the non-significant effects of lycopene and FruHis, it seems that FruHis intake strengthens the beneficial effects of lycopene on IGF-1, TPSA, and symptom scores among BPH patients.

CLINICAL TRIAL REGISTRATION

[www.irct.ir], identifier [IRCT20190522043669N1].

Multifunctional Gold Helix Phototheranostic Biohybrid That Enables Targeted Image-Guided Photothermal Therapy in Breast Cancer

The preparation of multifunctional smart theranostic systems is commonly achieved through complicated strategies, limiting their biomedical applications. Spirulina platensis (SP) microalgae, as a natural helix with some of the intrinsic theranostic functionalities (e.g., fluorescent and photosensitizer pigments), not only facilitates the fabrication process but also guarantees their biosafety for clinical applications. Herein, the helical architecture of gold nanoparticles (AuNPs) based on a SP biotemplate was engineered as a safe, biodegradable, and tumor-targeted biohybrid for imaging-guided photothermal therapy (PTT) to combat triple-negative breast cancer. The quasi-spherical AuNPs were embedded throughout the SP cell (Au-SP) with minimally involved reagents, only by controlling the original morphological stability of SP through pH adjustment of the synthesis media. SP thiolation increased the localization of AuNPs selectively on the cell wall without using a reducing agent (Au-TSP). SP autofluorescence, along with the high X-ray absorption of AuNPs, was employed for dual-modal fluorescence and computed tomography (FL/CT) imaging. Furthermore, the theranostic efficacy of Au-SP was improved through a targeting process with folic acid (Au-SP@CF). High tumor inhibition effects were obtained by the excellent photothermal performance of Au-SP@CF in both in vitro and in vivo analyses. Of particular note, a comparison of the photothermal effect of Au-SP@CF with the naked SP and calcined form of Au-SP@CF not only indicated the key role of the helical architecture of AuNPs in achieving a high photothermal effect but also led to the formation of new gold microspiral biohybrids (Au-MS) over the calcination process. In short, well-controllable immobilization of AuNPs, appropriate biodegradability, good hemocompatibility, long-term biosafety, accurate imaging, high tumor suppression, and low tumor metastasis effects under laser irradiation are an array of intriguing attributes, making the proposed biohybrid a promising theranostic system for FL/CT-imaging-guided PTT.

Investigating the attenuating effect of telmisartan against radiation-induced intestinal injury using 18F-FDG micro-PET imaging

BACKGROUND AND OBJECTIVE

This study was aimed to investigate the ability of ¹⁸F-Fluro-deoxy-glucose (¹⁸F-FDG)-based micro-positron emission tomography (microPET) imaging to evaluate the efficacy of telmisartan, a highly selective angiotensin II receptor antagonist (ARA), in intestinal tissue recovery process after in vivo irradiation.

METHODS

Male Balb/c mice were randomly divided into four groups of control, telmisartan, irradiation, and telmisartan + irradiation. A solution of telmisartan in phosphate-buffered saline (PBS) was administered orally at 12 mg/kg body weight for seven consecutive days prior to whole body exposing to a single sub-lethal dose of 5 Gy X-rays. The mice were imaged using ¹⁸F-FDG microPET at 9 and 30 days post-irradiation. The ¹⁸F-FDG uptake in jejunum was determined according to the mean standardized uptake value (SUVmean) index. Tissues were also processed in similar time points for histological analysis.

RESULTS

The ¹⁸F-FDG microPET imaging confirmed the efficacy of telmisartan as a potent attenuating agent for ionizing radiation-induced injury of intestine in mice model. The results were also in line with the histological analysis indicating that pretreatment with telmisartan reduced damage to the villi, crypts, and intestinal mucosa compared with irradiated and non-treated group from day 9 to 30 after irradiation.

CONCLUSION

The results revealed that ¹⁸F-FDG microPET imaging could be a good candidate to replace time-consuming and invasive biological techniques for screening of radioprotective agents. These findings were also confirmed by histological examinations which indicated that telmisartan can effectively attenuates radiation injury caused by ionizing-irradiation.

Novel Coumarin–Pyridine Hybrids as Potent Multi-Target Directed Ligands Aiming at Symptoms of Alzheimer’s Disease

In this research, a series of coumarin-based scaffolds linked to pyridine derivatives via a flexible aliphatic linkage were synthesized and assessed as multifunctional anti-AD agents. All the compounds showed acceptable acetylcholinesterase (AChE) inhibition activity in the nanomolar range (IC50 = 2–144 nM) and remarkable butyrylcholinesterase (BuChE) inhibition property (IC50 = 9–123 nM) compared to donepezil as the standard drug (IC50 = 14 and 275 nM, respectively). Compound 3f as the best AChE inhibitor (IC50 = 2 nM) showed acceptable BuChE inhibition activity (IC50 = 24 nM), 100 times more active than the standard drug. Compound 3f could also significantly protect PC12 and SH-SY5Y cells against H2O2-induced cell death and amyloid toxicity, respectively, superior to the standard drugs. It could interestingly reduce β-amyloid self and AChE-induced aggregation, more potent than the standard drug. All the results suggest that compound 3f could be considered as a promising multi-target-directed ligand (MTDL) against AD.

Histopathological Evaluation of Protective Effect of Telmisartan against Radiation-Induced Bone Marrow Injury

BACKGROUND

Radiation-induced hematopoietic suppression and myelotoxicity can occur due to the nuclear accidents, occupational irradiation and therapeutic interventions. Bone marrow dysfunction has always been one of the most important causes of morbidity and mortality after ionizing irradiation.

OBJECTIVE

This study aims to investigate the protective effect of telmisartan against radiation-induced bone marrow injuries in a Balb/c mouse model.

MATERIAL AND METHODS

In this experimental study, male Balb/c mice were divided into four groups as follow: group 1: mice received phosphate buffered saline (PBS) without irradiation, group 2: mice received a solution of telmisartan in PBS without irradiation, group 3: mice received PBS with irradiation, and group 4: mice received a solution of telmisartan in PBS with irradiation. A solution of telmisartan was prepared and administered orally at 12 mg/kg body weight for seven consecutive days prior to whole body exposing to a single sub-lethal dose of 5 Gy X-rays. Protection of bone marrow against radiation induced damage was investigated by Hematoxylin-Eosin (HE) staining assay at 3, 9, 15 and 30 days after irradiation.

RESULTS

Histopathological analysis indicated that administration of telmisartan reduced X-radiation-induced damage and improved bone marrow histology. The number of different cell types in bone marrow, including polymorphonuclear /mononuclear cells and megakaryocytes significantly increased in telmisartan treated group compared to the only irradiated group at all-time points.

CONCLUSION

The results of the present study demonstrated an efficient radioprotective effect of telmisartan in mouse bone marrow against sub-lethal X-irradiation.

Detection of glioblastoma multiforme using quantitative molecular magnetic resonance imaging based on 5-aminolevulinic acid: in vitro and in vivo studies

OBJECTIVES

We demonstrated a novel metabolic method based on sequential administration of 5-aminolevulinic acid (ALA) and iron supplement, and ferric ammonium citrate (FAC), for glioblastoma multiforme (GBM) detection using R₂' and quantitative susceptibility mapping (QSM).

MATERIALS AND METHODS

Intra-cellular iron accumulation in glioblastoma cells treated with ALA and/or FAC was measured. Cell phantoms containing glioblastoma cells and Wistar rats bearing C₆ glioblastoma were imaged using a 3 T MRI scanner after sequential administration of ALA and FAC. The relaxivity and QSM analysis were performed on the images.

RESULTS

The intra-cellular iron deposition was significantly higher in the glioma cells with sequential treatment of ALA and FAC for 6 h compared to those treated with the controls. The relaxivity and magnetic susceptibility values of the glioblastoma cells and rat brain tumors treated with ALA + FAC (115 ± 5 s-1 for R₂', and 0.1 ± 0.02 ppm for magnetic susceptibility) were significantly higher than those treated with the controls (55 ± 18 (FAC), 45 ± 15 (ALA) s-1 for R₂', p < 0.05, and 0.03 ± 0.03 (FAC), 0.02 ± 0.02 (ALA) ppm for magnetic susceptibility, p < 0.05).

DISCUSSION

Sequential administration of ALA and iron supplements increases the iron deposition in glioblastoma cells, enabling clinical 3 T MRI to detect GBM using R₂' or QSM.

Synthesis of New 3-Arylcoumarins Bearing N-Benzyl Triazole Moiety: Dual Lipoxygenase and Butyrylcholinesterase Inhibitors With Anti-Amyloid Aggregation and Neuroprotective Properties Against Alzheimer’s Disease

A novel series of coumarin derivatives linked to the N-benzyl triazole group were synthesized and evaluated against 15-lipoxygenase (15-LOX), and acetyl- and butyrylcholinesterase (AChE and BuChE) to find the most potent derivative against Alzheimer’s disease (AD). Most of the compounds showed weak to moderate activity against ChEs. Among the most active BuChE and 15-LOX inhibitors, 8l and 8n exhibited an excellent neuroprotective effect, higher than the standard drug (quercetin) on the PC12 cell model injured by H2O2 and significantly reduced aggregation of amyloid Aβ1-42, with potencies of 1.44 and 1.79 times higher than donepezil, respectively. Compound 8l also showed more activity than butylated hydroxytoluene (BHT) as the reference antioxidant agent in reducing the levels of H2O2 activated by amyloid β in BV2 microglial cells. Kinetic and ligand–enzyme docking studies were also performed for better understanding of the mode of interaction between the best BuChE inhibitor and the enzyme. Considering the acceptable BuChE and 15-LOX inhibition activities as well as significant neuroprotection, and anti-amyloid aggregation activities, 8l and 8n could be considered as potential MTDLs for further modification and studies against AD.

The effect of photodynamic therapy on head and neck squamous cell carcinoma cell lines using spirulina platensis with different laser energy densities

BACKGROUND

Considering the anti-cancer properties of spirulina platensis (S. platensis), we aimed to investigate the effectiveness of this algae as a novel natural photosensitizer for photodynamic therapy (PDT) against oral and hypopharyngeal cancer cells. The appropriate laser energy density to apply during PDT was also determined.

METHODS AND MATERIALS

CAL-27, FaDu and HGF cell lines were exposed to S. platensis with concentrations of 0.3 g/l and 0.6 g/l and were irradiated with 635 nm diode laser using 2, 4, 12, and 24 J/cm² energy densities with constant power. MTT assay was performed to investigate cell viability and cytotoxicity after 24 h. The results were analyzed using two-way ANOVA and post hoc Tukey tests (P-value<0.05).

RESULTS

survival rate in CAL-27 (P-Value<0.001) and FaDu (P-Value<0.001) cell lines were significantly different following irradiation with various laser energy densities. Different concentrations of S. platensis had no significant effect on the viability of CAL-27 cells (P-Value=0.158) and FaDu cells (P-Value=0.072) and showed no significant cytotoxicity against HGF cells, with or without laser.

CONCLUSION

S. platensis could be considered as a novel safe and effective natural photosensitizer for cancer PDT with no cytotoxic effect on normal cells. When combined with laser using appropriate energy densities, it has the ability to induce death in oral and hypopharyngeal cancer cell lines.

Synthesis of Pyrazolo[1,2-b]phthalazine-5,10- dione Derivatives: A New Class of α –Glucosidase Inhibitors

Background: Hyperglycemia is a metabolic disorder that refers to an increase in blood sugar in diabetic patients. α-Glucosidase has been introduced as a membrane-bound enzyme, and it is the main enzyme for carbohydrate digestion in some parts of the intestine. Inhibition of α -glucosidase enzyme activity is a reliable approach to control post-prandial hyperglycemia condition. Objectives: In this study, a series of Pyrazolo[1,2-b]phthalazine-5,10-dione derivatives 5a–t were synthesized via a multicomponent reaction and evaluated as new inhibitors for α-glucosidase. Methods: The biological activity of the synthesized compounds was studied using a source of the α-glucosidase enzyme (EC3.2.1.20, Saccharomyces cerevisiae) at 20 U/mg concentration. Results: Four compounds showed higher α-glucosidase inhibitory activity in comparison to a standard, i.e., Acarbose. Compound 5q displays the most potent α-glucosidase inhibitory activity (IC50 = 155.4 ± 6.0 μM). Conclusion: In conclusion, some of the synthesized compounds, including heterocyclic core molecules, have shown remarkable activity that could be considered as subjects for the development of new, more efficient inhibitors of the α-glucosidase enzyme.

Conjugated Linoleic Acid-Curcumin Attenuates Cognitive Deficits and Oxidative Stress Parameters in the Ethidium Bromide-Induced Model of Demyelination

Oxidative stress has been shown to play an important role in the pathogenesis of multiple sclerosis (MS). Curcumin (CUR), an antioxidant compound, can be a potent treatment for neurodegenerative diseases, such as MS. CUR has poor bioavailability; therefore, it is used in nanoforms to increase its bioavailability. In the present study, the effects of CUR and conjugated linoleic acid-CUR (Lino-CUR) on spatial memory and oxidative stress in a putative animal model of MS were investigated. Forty-nine adult male Wistar rats (250 ± 50 g) were randomly divided into seven groups (n = 7): control, sham, ethidium bromide (EB), CUR (20 and 40 μg/kg) + EB, and Lino-CUR (20 and 40 μg/kg) + EB groups. Following MS induction, the groups were treated for 5 consecutive days. Finally, spatial memory and levels of oxidative stress parameters were assessed. Treatment with CUR and Lino-CUR at two doses significantly improved spatial memory and reduced oxidative stress parameters in the experimental models of MS. Furthermore, the effects of high dose (40 μg/kg) of Lino-CUR were more remarkable. These findings suggest that the microinjection of CUR in its synthetic form Lino-CUR significantly ameliorated spatial memory, through the reduction of oxidative stress markers in the brain of studied animals as a rat model of MS.

The situation of small molecules targeting key proteins to combat SARS-CoV-2: Synthesis, metabolic pathway, mechanism of action, and potential therapeutic applications

Due to the global epidemic and high mortality of 2019 coronavirus disease (COVID-19), there is an immediate need to discover drugs that can help before a vaccine becomes available. Given that the process of producing new drugs is so long, the strategy of repurposing existing drugs is one of the promising options for the urgent treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19 disease. Although FDA has approved Remdesivir for the use in hospitalized adults and pediatric patients suffering from COVID-19, no fully effective and reliable drug has been yet identified worldwide to treat COVID-19 specifically. Thus, scientists are still trying to find antivirals specific to COVID-19. This work reviews the chemical structure, metabolic pathway, mechanism of action of existing drugs with potential therapeutic applications for COVID-19. Further, we summarized the molecular docking stimulation of the medications related to key protein targets. These already drugs could be developed for further clinical trials to supply suitable therapeutic options for patients suffering from COVID-19.

In vitro Anti-HIV-1 Activity of the Recombinant HIV-1 TAT Protein Along With Tenofovir Drug

BACKGROUND

HIV-1 TAT protein is essential for the regulation of viral genome transcription. The first exon of TAT protein has a fundamental role in the stimulation of the extrinsic and intrinsic apoptosis pathways, but its anti-HIV activity is not clear yet.

METHODS

In the current study, we firstly cloned the first exon of the TAT coding sequence in the pET-24a expression vector and then protein expression was done in the Rosetta expression host. Next, the expressed TAT protein was purified by Ni-NTA column under native conditions. After that, the protein yield was determined by Bradford kit and NanoDrop spectrophotometry. Finally, the cytotoxicity effect and anti-Scr-HIV-1 activity of the recombinant TAT protein alone and along with Tenofovir drug were assessed by MTT and ELISA, respectively.

RESULTS

The recombinant TAT protein was successfully generated in E. coli, as confirmed by 13.5% SDS-PAGE and western blotting. The protein yield was ~150-200 μg/ml. In addition, the recombinant TAT protein at a certain dose with low toxicity could suppress Scr-HIV replication in the infected HeLa cells (~30%) that was comparable with a low toxic dose of Tenofovir drug (~40%). It was interesting that the recombinant TAT protein could enhance anti-HIV potency of Tenofovir drug up to 66%.

CONCLUSION

Generally, a combination of TAT protein and Tenofovir drug could significantly inhibit HIV-1 replication. It will be required to determine their mechanism of action in the next studies.

Chromone-lipoic acid conjugate: Neuroprotective agent having acceptable butyrylcholinesterase inhibition, antioxidant and copper-chelation activities

PURPOSE

Alzheimer's disease (AD) is a multifaceted neurodegenerative disease. To target simultaneously multiple pathological processes involved in AD, natural-origin compounds with unique characteristics are promising scaffolds to develop novel multi-target compounds in the treatment of different neurodegenerative disease, especially AD. In this study, novel chromone-lipoic acid hybrids were prepared to find a new multifunctional lead structure for the treatment of AD.

METHODS

Chromone-lipoic acid hybrids were prepared through click reaction and their neuroprotection and anticholinesterase activity were fully evaluated. The anti-amyloid aggregation, antioxidant and metal-chelation activities of the best compound were also investigated by standard methods to find a new multi-functional agent against AD.

RESULTS

The primary biological screening demonstrated that all compounds had significant neuroprotection activity against H2O2-induced cell damage in PC12 cells. Compound 19 as the most potent butyrylcholinesterase (BuChE) inhibitor (IC50 = 7.55 μM) having significant neuroprotection activity as level as reference drug was selected for further biological evaluations. Docking and kinetic studies revealed non-competitive mixed-type inhibition of BuChE by compound 19. It could significantly reduce formation of the intracellular reactive oxygen species (ROS) and showed excellent reducing power (85.57 mM Fe+2), comparable with quercetin and lipoic acid. It could also moderately inhibit Aβ aggregation and selectively chelate with copper ions in 2:1 M ratio.

CONCLUSION

Compound 19 could be considered as a hopeful multifunctional agent for the further development gainst AD owing to the acceptable neuroprotective and anti-BuChE activity, moderate anti-Aβ aggregation activity, outstanding antioxidant activity as well as selective copper chelation ability. A new chromone-lipoic acid hybrid was synthesized as anti-Alzheimer agent with BuChE inhibitory activity, anti-Aβ aggregation, metal-chelation and antioxidant properties.

Magnetic carnosine-based metal-organic framework nanoparticles: fabrication, characterization and application as arsenic adsorbent

This study centers on the controllable synthesis, characterization, and application of a novel magnetic bio-metal-organic framework (Bio-MOF) for the adsorption and subsequent removal of arsenic from aqueous solutions. Zinc ions and carnosine (Car) were exploited to construct the Car-based MOF on the surface of magnetite (Fe₃O₄ NPs). The Magnetite precoating with Car led to an increase in the yield and the uniform formation of the magnetic MOF. The prepared magnetic Bio-MOF nanoparticles (Fe₃O₄-Car-MOF NPs) had semi-spherical shape with the size in the range of 35-77 nm, and the crystalline pattern of both magnetite and Car-based MOF. The NPs were employed as an adsorbent for arsenic (As) removal. The adsorption analyses revealed that all studied independent variables including pH, adsorbent dose, and initial arsenic concentration had a significant effect on the arsenic adsorption, and the adsorption data were well matched to the quadratic model. The predicted adsorption values were close to the experimental values confirming the validity of the suggested model. Furthermore, adsorbent dose and pH had a positive effect on arsenic removal, whereas arsenic concentration had a negative effect. The adsorption isotherm and kinetic studies both revealed that As adsorption fitted best to the Freundlich isotherm model. The maximum monolayer adsorption capacity (94.33 mg/g) was achieved at room temperature, pH of 8.5 and adsorbent dose of 0.4 g/L. Finally, the results demonstrated that the adsorbent could be efficiently applied for arsenic removal from aqueous environment.

A biocompatible theranostic nanoplatform based on magnetic gadolinium-chelated polycyclodextrin: in vitro and in vivo studies

A novel theranostic nanoplatform was prepared based on Fe₃O₄ nanoparticles (NPs) coated with gadolinium ions decorated-polycyclodextrin (PCD) layer (Fe₃O₄@PCD-Gd) and employed for Curcumin (CUR) loading. The dissolution profile of CUR indicated a pH sensitive release manner. Fe₃O₄@PCD-Gd NPs exhibited no significant toxicity against both normal and cancerous cell lines (MCF 10A and 4T1, respectively); while the CUR-free NPs showed more toxicity against 4T1 than MCF 10A cells. In vivo anticancer study revealed appropriate capability of the system in tumor shrinking with no tissue toxicity and adverse effect on body weight. In vivo MR imaging of BALB/c mouse showed both T₁ and T₂ contrast enhancement on the tumor cells. Fe₃O₄@PCD-Gd/CUR NPs showed significant features as a promising multifunctional system having appropriate T₁-T₂ dual contrast enhancement and therapeutic efficacy in cancer theranostics.

Surface modification and bioconjugation of anti-CD4 monoclonal antibody to magnetic nanoparticles as a highly efficient affinity adsorbent for positive selection of peripheral blood T CD4+ lymphocytes

Magnetic activated cell sorting (MACS) is a straightforward and time-saving procedure for isolation of different healthy functional cells. The present study aimed for the developing of a new MACS-based platform for isolation of peripheral blood T CD4+ lymphocytes. For this goal, first: Fe₃O₄ magnetic nanoparticles (MNP) were prepared by co-precipitation of Fe (III) and Fe (II) ions and then coated by SiO₂ shell, followed by the grafting of N-(phosphonomethyl) iminodiacetic acid (PMIDA) on the surface of fabricated MNP, Fe₃O₄@SiO₂@PMIDA were formed. These MNP were further tested for their ability to bind CD4 T lymphocytes. Through conjugation of the anti-CD4 monoclonal antibody on the surface of Fe₃O₄@SiO₂@PMIDA MNP. The newly developed immunomagnetic particles efficiently isolated T CD4+ lymphocytes from whole blood with high purity Therefore, our MNP afford an efficient tool for the cell separation process and further present the dramatic potential to be applied to other areas of biomedical application.

Coumarin-based Scaffold as α-glucosidase Inhibitory Activity: Implication for the Development of Potent Antidiabetic Agents

BACKGROUND

Delaying the absorption of glucose through α-glucosidase enzyme inhibition is one of the therapeutic approaches in the management of Type 2 diabetes, which can reduce the incidence of postprandial hyperglycemia. The existence of chronic postprandial hyperglycemia impaired the endogenous antioxidant defense by inducing oxidative stress-induced pancreatic β-cell destruction through uncontrolled generation of free radicals such as ROS, which in turn, leads to various macrovascular and microvascular complications. The currently available α -glucosidase inhibitors, for instance, acarbose, have some side effects such as hypoglycemia at higher doses, liver problems, meteorism, diarrhea, and lactic acidosis. Therefore, there is an urgent need to discover and develop potential α-glucosidase inhibitors.

OBJECTIVE

Based on suchmotifs, researchers are intrigued to search for the best scaffold that displays various biological activities. Among them, coumarin scaffold has attracted great attention. The compound and its derivatives can be isolated from various natural products and/or synthesized for the development of novel α-glucosidase inhibitors.

RESULTS

This study focused on coumarin and its derivatives as well as on their application as potent antidiabetic agents and has also concentrated on the structure-activity relationship.

CONCLUSION

This review describes the applications of coumarin-containing derivatives as α - glucosidase inhibitors based on published reports which will be useful for innovative approaches in the search for novel coumarin-based antidiabetic drugs with less toxicity and more potency.

Accompanying photocytotoxic activity of gold nanoechinus and zinc phthalocyanine on cancerous cell lines

BACKGROUND

Near-infrared triggered photodynamic therapy (NIR-PDT) has been introduced as a relatively deep tumor treatment modality. The gold Nanoechinus (Au NE) is a rare type of nanostructures that act as a transducer to change NIR wavelength to ultraviolet (UV) and visible lights. During the photodynamic process, Au nanoechinus (Au NE) converts the irradiation of 980 nm to 674 nm which is absorbed by Zn(II) Phthalocyanine tetrasulfonic acid (ZnPcS). In this study the cooperation effect of Au NE and ZnPcS in PDT on MCF7 and Hela cells was investigated.

METHODS

Cytotoxicity and phototoxicity of the composition having different concentrations of Au NE and ZnPcS upon irradiation of 980 nm NIR light were evaluated against MCF7 and Hela cells after two different incubation times and irradiating with two different power densities of laser.

RESULTS

Among different experimental groups, in MCF7 cells, which were incubated for 48 h with 50 μg/mL Au NE+2μM ZnPcS and were treated by 980 nm laser with a power density of 200 mW cm^-2 for 15 and 30 min, 48 and 38% cell viability were recorded. No appreciable result was observed due to PDT of Hela cells.

CONCLUSIONS

Comparing to other PDT modalities against MCF7 cells, NIR-PDT procedure suggested in this study with the synergistic effect of Au NE and ZnPcS could be a secure promising modality in the treatment of deep-seated tumors. Carefully increasing the power density and ambient temperature, to the extent of skin tolerance threshold value, seems to be efficient in the treatment of Hela cells.

Cytotoxic Activity and DNA Binding Property of New Aminopyrimidine Derivatives

Background:

Chromene and anilinopyrimidine heterocyclics are attractive anticancer compounds that have inspired many researchers to design novel derivatives bearing improved anticancer activity.

Methods:

A series of pyrimidine-fused benzo[f]chromene derivatives 6a-x were synthesized as anticancer hybrids of 1H-benzo[f]chromenes and anilinopyrimidines. The inhibitory activity of the synthesized compounds 6a-x against cell viability of human chronic myelogenous leukemia (K562), human acute lymphoblastic leukemia (MOLT-4) and human breast adenocarcinoma (MCF-7) cell lines was evaluated using MTT assay. The interaction of the most promising compound with calf-thymus DNA was also studied using spectrometric titrations and Circular Dichroism (CD) spectroscopy.

Results:

Most compounds showed promising activity against tested cell lines. Among them, 2,4- dimethoxyanilino derivative 6g exhibited the best profile of activity against tested cell lines (IC50s = 1.6-6.1 μM) with no toxicity against NIH3T3 normal cell (IC50 >200 μM). The spectrometric studies exhibited that compound 6g binds to DNA strongly and may change DNA conformation significantly, presumably via a groove binding mechanism.

Conclusion:

The results of this study suggest that the prototype compound 6g can be considered as a novel lead compound for the design and discovery of novel anticancer agents.

Poly-l-lactic acid scaffold incorporated chitosan-coated mesoporous silica nanoparticles as pH-sensitive composite for enhanced osteogenic differentiation of human adipose tissue stem cells by dexamethasone delivery

Nowadays, the development of drug-loaded electrospun organic-inorganic composite scaffolds for tissue engineering application is an attractive approach. In this study, a composite scaffold of Poly-l-lactic acid (PLLA) incorporated dexamethasone (Dexa) loaded Mesoporous Silica Nanoparticles (MSN) coated with Chitosan (CS) were fabricated by electrospinning for bone tissue engineering application. The MSN was prepared by precipitation method. After that, Dexamethasone (Dexa) was loaded into MSNs (MSN-Dexa). In the following, CS was coated over the prepared nanoparticles to form MSN-Dexa@CS and then, were mixed to PLLA solution to form MSN-Dexa@CS/PLLA composite for electrospinning. The surface morphology, hydrophilicity, tensile strength and the bioactivity of the scaffolds were characterized. The osteogenic proliferation and differentiation potential were evaluated by MTT assay and by measuring the basic osteogenic markers: the activity of the enzyme alkaline phosphatase and the level of calcium deposition. The composite scaffolds prepared here have conductive surface property and have a better osteogenic potential than pure PLLA scaffolds. Hence, the controlled release of nanoparticle containing Dexa from composite scaffold supported the osteogenesis and made the composite scaffolds ideal candidates for bone tissue engineering application and pH-sensitive delivery of drugs at the site of implantation in tissue regeneration.

Photocatalytic degradation of ketoconazole by Z-scheme Ag3PO4/graphene oxide: response surface modeling and optimization

Ketoconazole is an imidazole fungicide which is commonly used as pharmaceutical and healthcare products. Residual amount of this compound can cause adverse ecological health problems. The present study investigated ketoconazole photocatalytic degradation using Ag₃PO₄/graphene oxide (GO). Ag₃PO₄/GO and Ag₃PO₄ as visible light-driven photocatalysts was synthesized using the in situ growth method. Degradation of ketoconazole at the concentration of 1-20 mg/L in aqueous solutions was optimized in the presence of Ag₃PO₄/GO nanocomposite with the dosage of 0.5-2 g/L, contact time of 15-20 min, and pH of 5-9 using response surface methodology. A second-order model was selected as the best fitted model with R² value and lack of fit as 0.935 and 0.06, respectively. Under the optimized conditions, the Ag₃PO₄/GO catalyst achieved a photocatalytic efficiency of 96.53% after 93.34 min. The photocatalytic activity, reaction kinetics, and stability were also investigated. The results indicated that the Ag₃PO₄/GO nanocomposite exhibited higher photocatalytic activity for ketoconazole degradation, which was 2.4 times that of pure Ag₃PO₄. Finally, a direct Z-scheme mechanism was found to be responsible for enhanced photocatalytic activity in the Ag₃PO₄/GO nanocomposite. The high photocatalytic activity, acceptable reusability, and good aqueous stability make the Ag₃PO₄/GO nanocomposite a promising nanophotocatalyst for photocatalytic degradation of azoles contaminants.

Multifunctional MIL-Cur@FC as a theranostic agent for magnetic resonance imaging and targeting drug delivery: in vitro and in vivo study

Owing to the importance of multifunctional theranostics as promising systems to overcome key problems of conventional cancer therapy, in this study a multifunctional metal-organic framework-based (MOF) theranostic system was prepared and applied as intelligent theranostic systems in cancer. Iron-based MOF, MIL-88B, in a multi-faceted shape was initially prepared. Curcumin (Cur) was then loaded into the pores of MIL and folic acid-chitosan conjugate (FC) was finally coated on the surface of the carrier to accomplish cancer-specific targeting properties. MTT assay revealed perfect cytocompatibility of the system and selective toxicity against cancerous cells. In vivo MRI images showed high tumour uptake for MIL-Cur@FC and high T₁-T₂ contrast effect. The growth inhibiting efficiencies of MIL-Cur@FC on M109 tumour bearing Balb/C mice without reducing their body weight showed maximum tumour eradication with no significant toxicities. Due to the outstanding features of the system achieved from in vitro and in vivo studies, we believe that this study will provide a novel approach for developing targeted theranostic agents in cancer diagnosis and treatment.

In vitro and in vivo characteristics of doxorubicin-loaded cyclodextrine-based polyester modified gadolinium oxide nanoparticles: a versatile targeted theranostic system for tumour chemotherapy and molecular resonance imaging

β-Cyclodextrine-based polyester was coated on the surface of gadolinium oxide nanoparticles (NPs) and then functionalised with folic acid to produce an efficient pH-sensitive targeted theranostic system (Gd₂O₃@PCD-FA) for doxorubicin delivery and magnetic resonance imaging (MRI). Gd₂O₃@PCD-FA was fully characterised by FTIR, vibrating sample magnetometer, TGA, XRD, SEM and TEM analyses. The dissolution profile of DOX showed a pH sensitive release. No significant toxicity was observed for the targeted NPs (Gd₂O₃@PCD-FA) and DOX-loaded NPs inhibiting M109 cells viability more efficiently than free DOX. Moreover, the negligible hemolytic activity of the targeted NPs showed their appropriate hemocompatibility. The preferential uptake was observed for the developed Gd₂O₃@PCD-FA-DOX NPs in comparison with Dotarem using T₁- and T₂-weighted MRI in the presence of folate receptor-positive and folate receptor-negative cancer cells (M109 and 4T1, respectively). Furthermore, in vivo studies revealed that Gd₂O₃@PCD-FA-DOX not only exhibited considerably relaxivity performance as a contrast agent for MRI, but also improved in vivo anti-tumour efficacy of the system. The results suggest that Gd₂O₃@PCD-FA-DOX improves its therapeutic efficacy in the treatment of solid tumours and also reduces the adverse effects, so it could be proposed as a promising drug delivery system for chemotherapy and molecular imaging diagnosis in MRI.

Preparation of PEG-grafted chitosan/streptokinase nanoparticles to improve biological half-life and reduce immunogenicity of the enzyme

Streptokinase, as a thrombolytic drug, is widely used in treatment of cardiovascular disorders and deep vein thrombosis. Streptokinase is immunogenic due to its prokaryotic source, having short biological half-life (i.e. 15 to 30 min) that is not enough for an efficient therapy. In this study, nanoparticles (NPs) of chitosan/streptokinase and polyethylene glycol (PEG)-grafted chitosan/streptokinase were prepared by polyelectrolyte complex method. Particle size of chitosan and PEG-grafted chitosan NPs were 154 ± 42 and 211 ± 47 nm, respectively. Results showed that using PEG in preparation of nanoparticles leads to ~24% decrease in encapsulation efficiency. Encapsulation of streptokinase in the NPs also resulted in a slight reduction in enzymatic activity. However, in vivo findings indicated that response of the immune system was delayed for 20 days and blood circulation time of the enzyme increased up to 120 min by using PEG. Biological half-life of the drug also increased up to twice in PEG-grafted chitosan. In conclusion, PEG-grafted chitosan NPs could be an alternative for delivery of streptokinase to reduce its clinical limitations.