Suppression of Inflammation-Associated Kidney Damage Post-Transplant Using the New PrC-210 Free Radical Scavenger in Rats.

Allograft kidney transplantation, which triggers host cellular- and antibody-mediated rejection of the kidney, is a major contributor to kidney damage during transplant. Here, we asked whether PrC-210 would suppress damage seen in allograft kidney transplant. Brown Norway (BN) rat kidneys were perfused in situ (UW Solution) with or without added 30 mM PrC-210, and then immediately transplanted into Lewis (LEW) rats. 20 h later, the transplanted BN kidneys and LEW rat plasma were analyzed. Kidney histology, and kidney/serum levels of several inflammation-associated cytokines, were measured to assess mismatch-related kidney pathology, and PrC-210 protective efficacy. Twenty hours after the allograft transplants: (i) significant histologic kidney tubule damage and mononuclear inflammatory cell infiltration were seen in allograft kidneys; (ii) kidney function metrics (creatinine and BUN) were significantly elevated; (iii) significant changes in key cytokines, i.e., TIMP-1, TNF-alpha and MIP-3A/CCL20, and kidney activated caspase levels were seen. In PrC-210-treated kidneys and recipient rats, (i) kidney histologic damage (Banff Scores) and mononuclear infiltration were reduced to untreated background levels; (ii) creatinine and BUN were significantly reduced; and (iii) activated caspase and cytokine changes were significantly reduced, some to background. In conclusion, the results suggest that PrC-210 could provide broadly applicable organ protection for many allograft transplantation conditions; it could protect transplanted kidneys during and after all stages of the transplantation process-from organ donation, through transportation, re-implantation and the post-operative inflammation-to minimize acute and chronic rejection.

Toxicological evaluation of fluorescent 11-mercaptoundecanoic gold nanoclusters as promising label-free bioimaging probes in different cancer cell lines.

Due to advancement in nanomaterials and increasing use of functionalized gold nanoclusters (AuNCs) in different biomedical applications, better understanding of their potential cytotoxicity is necessary. Interactions of ultra-small fluorescent AuNCs with mammalian cells remains up to this day poorly understood, therefore, cytotoxic evaluation of thoroughly characterized ca. 2.5 nm spherical water-soluble 11-mercaptoundecanoic acid coated AuNCs (AuNC@M) with diverse fluorescent properties in variety of mammalian cancer cell lines was performed. Cell viability was assessed by traditional MTT assay and xCELLigence real time cell analyzer. Cell apoptosis was evaluated via an Annexin V-FITC/propidium iodide (PI) assay. Confocal fluorescence imaging confirmed that tested AuNC@M entered live cells and were homogeneously distributed in their cytoplasm. The results suggested that the cytotoxicity of tested nanoclusters was very low, or near the control level at concentrations 0.1 and 0.5 mg/mL in the cell lines after 24 h exposition. The purity of tested AuNC@M had no relevant effect on cell viability and no differences were observed after 24 h in our study. The low toxicity toward cancer cells further strengthens our view that AuNC@M are promising label-free fluorescent probes for bio-labelling and bio-imaging, or they can even serve as platforms for antitumor drug delivery systems.

Size-dependent biodistribution of thiol-organosilica nanoparticles and F4/80 protein expression in the genital tract of female mice after intravaginal administration.

Recently the vaginal route consider as an ideal route for drug delivery systems (DDS) administration. This is because, it is suitable for lower drug dosage, higher drug concentration in the genital tract tissues and lower drug concentration in pregnant women blood circulation. However, the vaginal route administration faces many challenges due to the physiology as well as the complexity of vaginal tissue histology. Here in this study, during diestrus stage (optimal condition for foreign substance internalization), single or dual size of fluorescent thiol-organosilica nanoparticles (tOS-NPs) were administrated intravaginally. The biodistribution and reactivity of tOS-NPs in different tissues of the female genital tract were investigated under the fluorescence microscope. Furthermore, using immunohistochemical staining, the expression of F4/80 protein and the role of macrophages in transport and re-location of tOS-NPs from vaginal lumen into different genital tissues or other organs were investigated. This study showed that, tOS-NPs size and type of tissue are important in biodistribution and uptake of tOS-NPs in the genital tract. Small size (100 nm) of tOS-NPs was highly accumulated in the genital tract tissues especially endometrial epithelium compared with large tOS-NPs (1000 nm). Contradictory, the large size induced the expression of F4/80 protein and the number of vaginal macrophages compared with small size. However, both small and large sizes of tOS-NPs were found co-localized with F4/80+ macrophages, located in the vaginal, endometrial and ovarian tissues. The tOS-NPs intravaginally administrated were found in the splenic tissues, indicating its ability to enter the blood circulation from the vaginal lumen. Additionally, the high accumulation of tOS-NPs in the endometrial epithelium indicated the endometrial first pass effect of tOS-NPs. As a result, high concentration of tOS-NPs in the endometrial epithelium may reduce the concentration of tOS-NPs-based DDS in the blood circulation and their side effects. Furthermore, during vaginal tissue optimal condition (diestrus stage), understanding the fate and biodistribution of tOS-NPs will introduce important data about the development of save and effective DDS for the pregnant women.

The influence of multiple oral administration on the pharmacokinetics and distribution profile of dalcetrapib in rats.

We investigated the influence of multiple oral administration on the accumulation of dalcetrapib (JTT-705/RO4607381), a novel cholesteryl ester transfer protein inhibitor, in rats. It is well known that orally administered dalcetrapib is rapidly hydrolysed to its active form, which has a sulfhydryl group, in the body. The active form then binds covalently to endogenous thiols via mixed disulfide bonds. Following multiple once daily oral administration of 14C-dalcetrapib for seven days to rats, the concentration of radioactivity in the plasma and almost all tissues reached the steady state by day 4. At 24 h after the last dose, there was a relatively high concentration of radioactivity in the mesenteric lymph nodes, liver, adrenal glands and fat. After the last dose to rats, the radioactivity was almost completely recovered in the urine and faeces, indicating that dalcetrapib is not retained in the body, probably due to the reversibility of the disulfide bonds despite being covalent bonds.

New multitarget directed benzimidazole-2-thiol-based heterocycles as prospective anti-radical and anti-Alzheimer's agents.

A series of new heterocycles (4-18) was synthesized by the structural modification of benzimidazole-2-thiol (BT, 2-MBI). The structures of the synthesized compounds were confirmed with the help of high-resolution mass spectrometry (HRMS) and 1 HNMR spectroscopy. High inhibitions of the oxidants such as ABTS and DPPH were observed for compounds 9 [IC50 (s) = 167.4 µM (ABTS), 139.5 µM (DPPH)], 10 [IC50 (s) = 186.5 µM (ABTS), 155.4 µM (DPPH)], 11 [IC50 (s) = 286.1 µM (ABTS), 189.1 µM (DPPH)], 12 [IC50 (s) = 310.8 µM (ABTS), 162.2 µM (DPPH)], 14 [IC50 (s) = 281.3 µM (ABTS), 205.7 µM (DPPH)], 15 [IC50 (s) = 284.1 µM (ABTS), 177.3 µM (DPPH)], and 16 [IC50 (s) = 344.7 µM (ABTS), 270.2 µM (DPPH)] as compared with Ascorbic acid [IC50 (s) = 340.9 µM (ABTS), 164.3 µM (DPPH)]. The anti-Alzheimer's activity was performed in vitro against cholinesterase enzymes (AChE, BChE). Compound 11 was able to show significant inhibitions [IC50 (s) = 121.2 µM (AChE), 38.3 µM (BChE)] as against that of galantamine [IC50 (s) = 139.4 µM (AChE), 40.3 µM (BChE)]. Compound 14 was found as a very good inhibitor of butyrylcholinesterase (IC50 = 35.4 µM) as compared with standard galantamine. Molecular docking was further performed to investigate the mechanism of anticholinesterase activity.

Optimization of preparation methods for high loading content and high encapsulation efficiency of BSH into liposomes.

To optimize the preparation methods for liposomes encapsulating mercaptoundecahydrododecaborate (BSH), we examined BSH and lipid concentrations that increased the boron content in liposomes. We improved the BSH encapsulation efficiency and boron content of the liposomes from 4.2 to 45.9 % and 9.5-54.3 µg, respectively, by changing the lipid concentration from 10 to 150 mg/mL. Notably, the boron content increased significantly from 26.2 µg to 326.3 µg at a constant lipid concentration of 30 mg/mL with increased BSH concentrations.

Integration of IR-808 and thiol-capped Au-Bi bimetallic nanoparticles for NIR light mediated photothermal/photodynamic therapy and imaging.

Near infrared (NIR) light detonated phototherapy for cancer treatment based on photothermal therapy (PTT) and photodynamic therapy (PDT) has attracted increasing attention owing to its deep tissue penetration. However, the low absorption ability and therapeutic efficiency of the photosensitive drug have restricted the development of phototherapy to a great degree. Herein, a kind of IR808 dye sensitized glutathione (GSH) cladded Au-Bi bimetallic nanoparticles (Au-Bi-GSH@IR808) was prepared to enhance the inhibition effect of tumors. In this nanoplatform, the construction of GSH cladded Au-Bi bimetallic nanoparticles can effectively generate 1O2 while exhibiting outstanding photothermal conversion efficiency (η = 34.2%) upon 808 nm laser irradiation. Furthermore, IR808 as a small molecule dye endows the Au-Bi-GSH@IR808 with a higher 808 nm light absorption ability and stronger photothermal and photodynamic effects. The IR808 sensitized Au-Bi bimetallic nanoparticles with a small size (5 nm), hydrophilia and dispersible nature, exhibit a noticeably enhanced therapeutic peculiarity. Additionally, the prominent CT imaging property of Au-Bi-GSH@IR808 means it is expected to be used as a CT imaging contrast agent in clinical applications. The results of the in vitro and in vivo experiments indicate that the synthesized nanoparticles have an excellent ablation effect on cancer cells, and they are expected to be widely used in the accurate diagnosis and treatment of cancer.

Rosmarinic acid prevents gastric ulcers via sulfhydryl groups reinforcement, antioxidant and immunomodulatory effects.

Rosmarinic acid (RA) is a secondary metabolite present in several plant species that has already demonstrated antioxidant, antiallergic, anticancer, antimicrobial, neuroprotective, and hepatoprotective effects experimentally. Due to the promising pharmacological properties found previously, this study aimed to assess the oral acute toxicity and the gastroprotective effect of RA using animal models. Acute toxicity was assessed according to OECD guide 423. Ethanol, stress, NSAIDs, and pylorus ligature-induced gastric ulcer models were used to investigate antiulcer properties. The related mechanisms of action were also evaluated from ethanol-induced gastric lesions protocol. RA (300 and 2000 mg/kg) showed no changes in behavioral, water and food intake, body and organs weight parameters with LD50 set around 2500 mg/kg. RA presented gastroprotective activity in all assessed doses (25, 50, 100, and 200 mg/kg) using different animal models. Besides, it was observed that this effect is not related to the modulation of gastric juice parameters (pH, volume, and [H+]), the participation of nitric oxide, mucus, and prostaglandins. However, increased sulfhydryl groups, GSH and IL-10 levels as well as reduced of proinflammatory cytokine (TNF-α and IL-1ß) levels were found for RA-treated groups. RA presents low acute toxicity and gastroprotective activity, preventing ulcer formation via cytoprotective, antioxidant, and anti-inflammatory mechanisms. Graphical abstract.

A disulfide based low molecular weight gel for the selective sustained release of biomolecules.

Constructing biocompatible soft materials via supramolecular approaches remains an important challenge for in vivo applications. Substantial efforts have been made to develop biocompatible non-polymeric materials allowing sustained release of biomolecules and/or drugs in vivo. Herein, we introduce disulfide based low molecular weight gels (LMWGs) allowing the in vitro selective sustained release of proteins containing thiol residues. The novel glycosylated nucleoside based bola-amphiphile (GNBA), which features a disulfide bond inserted in the hydrophobic segment, self-assembles to stabilize the resulting hydrogel. Rheological studies show the dominant elastic character and thixotropic properties of the disulfide LMWG demonstrating its injectability. In vitro and in vivo biodegradation investigations reveal that the disulfide LMWG is stable for several weeks. Importantly, disulfide bonds can be cleaved through the thiol-disulfide exchange reactions with small redox molecules such as dithiothreitol (DTT). The disulfide LMWG loaded with a thiol-containing protein (bovine serum albumin) features sustained release in vitro, whereas a dextran of the same molecular weight, lacking a thiol biomolecule, shows quick release. The disulfide GNBA is the first example of a LMWG allowing selective long term sustained release in vitro via a disulfide reshuffling mechanism.

Accelerator-based boron neutron capture therapy for malignant glioma: a pilot neutron irradiation study using boron phenylalanine, sodium borocaptate and liposomal borocaptate with a heterotopic U87 glioblastoma model in SCID mice.

Purpose: To evaluate the efficacy of boron neutron capture therapy (BNCT) for a heterotopic U87 glioblastoma model in SCID mice using boron phenylalanine (BPA), sodium borocaptate (BSH) and liposomal BSH as boron compounds at a unique, accelerator-based neutron source.Materials and methods: Glioblastoma models were obtained by subcutaneous implantation of U87 cells in the right thighs of SCID mice before administration of 350 mg/kg of BPA (BPA-group), 100 mg/kg of BSH (BSH-group) or 100 mg/kg of BSH in PEGylated liposomes (liposomal BSH-group) into the retroorbital sinus. Liposomes were prepared by reverse-phase evaporation. Neutron irradiation was carried out at a proton accelerator with a lithium target developed for BNCT at the Budker Institute of Nuclear Physics, Novosibirsk, Russian Federation. A proton beam current integral of 3 mA/h and energy of 2.05 MeV were used for neutron generation.Results: Boron compound accumulation in tumor tissues at the beginning of irradiation was higher in the BPA group, followed by the Liposomal BSH and BSH groups. Tumor growth was significantly slower in all irradiated mice from the 7th day after BNCT compared to untreated controls (p < .05). Tumor growth in all treated groups showed no large variation, apart from the Irradiation only group and the BPA group on the 7th day after BNCT. The overall trend of tumor growth was clear and the differences between treatment groups became significant from the 50th day after BNCT. Tumor growth was significantly slower in the Liposomal BSH group compared to the Irradiation only group on the 50th (p = .012), 53rd (p = .005), and the 57th (p = .021) days after treatment. Tumor growth in the Liposomal BSH group was significantly different from that in the BPA group on the 53rd day after BNCT (p = .021) and in the BSH group on the 50th (p = .024), 53rd (p = .015), and 57th (p = .038) days after BNCT. Skin reactions in the form of erosions and ulcers in the tumor area developed in treated as well as untreated animals with further formation of fistulas and necrotic decay cavities in most irradiated mice.Conclusions: We observed a tendency of BNCT at the accelerator-based neutron source to reduce or suspend the growth of human glioblastoma in immunodeficient animals. Liposomal BSH showed better long-term results compared to BPA and non-liposomal BSH. Further modifications in liposomal boron delivery are being studied to improve treatment outcomes.

Synthesis and in vitro characterization of a preactivated thiolated acrylic acid/acrylamide-methylpropane sulfonic acid copolymer as a mucoadhesive sprayable polymer.

AIM: Development of a preactivated thiomer as sprayable excipient for mucoadhesive formulations. METHODS: CG4500 (acrylic acid/acrylamide-methyl propane sulfonic acid copolymer) was thiolated by conjugation with L-cysteine and preactivated by further modification with 2-mercaptonicotinic acid (MNA) in a two-step synthesis and characterized regarding degree of modification and cytotoxicity on Caco-2 cells. The mucoadhesive properties of this novel thiomer were evaluated via rheological synergism, tensile and mucosal residence time studies. Furthermore, the sprayability of the thiomer was evaluated. RESULTS: The newly synthesized derivatives CG4500-SH and CG4500-S-S-MNA showed mean coupling rates of 651 µmol thiol groups and 264 µmol MNA per gram polymer, respectively. Even for the unmodified polymer a rheological synergism was observed with isolated porcine intestinal mucus, which was 2.81-fold higher in case of the preactivated thiomer. Mucoadhesion studies on freshly excised porcine intestinal mucosa confirmed these results via a 2.43-fold higher total work of adhesion and a 2.31-fold higher mucosal residence time of the preactivated thiomer. In sprayability tests it was shown that solutions of the preactivated thiomer could be sprayed in concentrations up to 12% (m/V). CONCLUSION: The novel polymer CG4500-S-S-MNA is a promising sprayable excipient for mucoadhesive formulations.

The ligand exchange of citrates to thioabiraterone on gold nanoparticles for prostate cancer therapy.

Cancer is one of the leading causes of morbidity and mortality worldwide and nanotechnology has a significant potential to enhance the therapeutic and diagnostic performance of anti-cancer agents. Our work offers a simple and feasible strategy for thiocompound nanomedicines to be used in cancer therapy. Novel gold nanoparticles conjugated with thioabiraterone (AuNP-S-AB) were synthesized and significant new analytical methodologies were developed for their characterization by UV-Vis, TEM, IR, NMR and TGA. Our synthetic approach was based on the ligand exchange of citrates to thioabiraterone on gold nanoparticles. The average particle size of AuNP-S-AB was 14.5 nm with a spherical shape. The identity of thioabiraterone on the gold nanoparticles was proved by NMR and IR spectroscopy. The coverage of the gold nanoparticles with 40.9% (m/m) thioabiraterone was calculated from a TGA analysis. Molecular interactions between the thiol group of thioabiraterone and gold nanoparticles were evaluated through a combined experimental and theoretical study using the density functional theory (DFT). Additionally, an experiment conducted on hepatocytes or human prostate epithelial cells proved that newly synthesized thiol forms of abiraterone, as well as AuNP-S-AB, are more biocompatible than abiraterone. Our proposed idea of delivering abiraterone with our newly designed AuNP-S-AB may constitute a promising and novel prospect in cancer therapy.

Therapeutic Efficacy of the N,N' Bis-(2-Mercaptoethyl) Isophthalamide Chelator for Methylmercury Intoxication in Caenorhabditis elegans.

Methylmercury (MeHg) is a global pollutant and potent neurotoxin. In humans, MeHg damages the central nervous system (CNS), causing irreversible neuronal shrinkage, and neuronal loss. Most chelators for clinical mercury detoxification are thiol-containing agents. N,N 'bis-(2-mercaptoethyl) isophthalamide (NBMI) is a lipophilic thiol agent synthesized from natural chemicals. NBMI has high affinity for mercury, cadmium and lead, and can decrease their concentrations in polluted water. However, the efficacy of NBMI for MeHg toxicity has yet to be evaluated in intact animals. Here we used the nematode Caenorhabditis elegans (C. elegans) to test the efficacy of NBMI in attenuating MeHg toxicity in vivo in the whole organism. The results showed that NBMI reduced both the acute toxicity (125 µM MeHg, 1 h) and chronic (5 µM MeHg, 24 h) MeHg toxicity. Co-treatment with NBMI achieved maximal efficacy against MeHg toxicity, however delayed treatment 6 days after initiation of exposure was also effective at reducing neurotoxicity. Co-treatment of NBMI reduced the worms' death rate, structural damage in DAergic neurons, and restored antioxidant response levels. While this study provides proof of principle for the therapeutic value of NBMI in MeHg toxicity, future studies are needed to address the cellular and molecular mechanisms and translatability of these effects to humans and other animals.

Biocompatible thiolate protected copper nanoclusters for an efficient imaging of lung cancer cells.

We report, the one-pot synthesis of water-soluble and biocompatible 3-mercaptopropylsulfonate (MPS) protected novel copper nanoclusters (CuNCs). Interestingly, the TEM image of MPS protected CuNCs exhibits an ultrasmall nanoclusters of particle size <2-nm, similar to its Au and Ag analogue. The hydrophilic and biocompability property of thiolate protected CuNCs. i.e., MPS stabilized CuNCs and its luminescent nature gave rise to maximum quantum yield of 1.5%. Further, as achieved CuNCs was investigated for haemocompatibility, cell viability and fluorescent microscopic analysis with A549 lung cancer cell line. Haemolytic study was examined using human RBCs in the concentration range of 4 to 22 µg/mL for which 7.5% of haemolysis was obtained for an optimum concentration of 22 µg/mL of CuNCs. The cell viability analysis was carried out by MTT assay using A549 lung cancer cells for the minimum (10 µg/mL) and maximum (45 µg/mL) concentration of CuNCs which reports 93.1% and 38.2% cell viability respectively. The inverted light microscopic images from the control and CuNCs treated (20 µg/mL) cells exhibited an excellent biocompatibility with a normal morphology. Upon increasing the concentration of CuNCs upto 45 µg/mL, the cell viability trends to decrease and the cell morphology also denature gradually. Further, the bio-imaging application of CuNCs was analyzed with A549 lung cancer cells. The efficient imaging with CuNCs treated (20 µg/mL) A549 cells resulted in a green colour emission using FITC filter (460- 490 nm). Thereby the obtained results confirm the applicability of CuNCs for the biomedical and cancer diagnosis applications.

Study design of Dal-GenE, a pharmacogenetic trial targeting reduction of cardiovascular events with dalcetrapib.

The objectives of precision medicine are to better match patient characteristics with the therapeutic intervention to optimize the chances of beneficial actions while reducing the exposure to unneeded adverse drug experiences. In a retrospective genome-wide association study of the overall neutral placebo-controlled dal-Outcomes trial, the effect of the cholesteryl ester transfer protein (CETP) modulator dalcetrapib on the composite of cardiovascular death, myocardial infarction or stroke was found to be influenced by a polymorphism in the adenylate cyclase type 9 (ADCY9) gene. Whereas patients with the AA genotype at position rs1967309 experienced fewer cardiovascular events with dalcetrapib, those with the GG genotype had an increased rate and the heterozygous AG genotype exhibited no difference from placebo. Measurements of cholesterol efflux and C-reactive protein (CRP) offered directionally supportive genotype-specific findings. In a separate, smaller, placebo-controlled trial, regression of ultrasonography-determined carotid intimal-medial thickness was only observed in dalcetrapib-treated patients with the AA genotype. Collectively, these observations led to the hypothesis that the cardiovascular effects of dalcetrapib may be pharmacogenetically determined, with a favorable benefit-risk ratio only for patients with this specific genotype. We describe below the design of dal-GenE, a precision medicine, placebo-controlled clinical outcome trial of dalcetrapib in patients with a recent acute myocardial infarction with the unique feature of selecting only those with the AA genotype at rs1967309 in the ADCY9 gene.

In situ self-assembly of conjugated polyelectrolytes for cancer targeted imaging and photodynamic therapy.

The construction of intelligent self-assembly systems with cancer targeting photodynamic therapy abilities is highly required for increasing the precise therapeutic efficiency in clinical treatment. Herein, a cationic water soluble conjugated polymer (PFT-SH) functionalized with thiol groups was designed and synthesized via a palladium-catalyzed Suzuki coupling reaction. Firstly, PFT-SH can enter cells and form loose aggregations by hydrophobic and π-π stacking interactions. Secondly, a high level of H2O2 in cancer cells oxidizes sulfhydryl groups to disulfide bonds and then forms more and larger aggregations. Finally, PFT-SH showed remarkable ROS producing ability under white light irradiation with 78% quantum yields (ΦΔ). Due to this unique self-aggregation property, PFT-SH was successfully used to achieve in situ self-assembly specifically inside cancer cells for targeted imaging. Both the specific aggregation of PFT-SH in cancer cells and its ROS producing ability led to its use in the targeted killing of cancer cells through efficient photodynamic therapy.

Medicinal Thiols: Current Status and New Perspectives.

The thiol (-SH) functional group is found in a number of drug compounds and confers a unique combination of useful properties. Thiol-containing drugs can reduce radicals and other toxic electrophiles, restore cellular thiol pools, and form stable complexes with heavy metals such as lead, arsenic, and copper. Thus, thiols can treat a variety of conditions by serving as radical scavengers, GSH prodrugs, or metal chelators. Many of the compounds discussed here have been in use for decades, yet continued exploration of their properties has yielded new understanding in recent years, which can be used to optimize their clinical application and provide insights into the development of new treatments. The purpose of this narrative review is to highlight the biochemistry of currently used thiol drugs within the context of developments reported in the last five years. More specifically, this review focuses on thiol drugs that represent the standard of care for their associated conditions, including N-acetylcysteine, 2,3-meso-dimercaptosuccinic acid, British anti-Lewisite, D-penicillamine, amifostine, and others. Reports of novel dosing regimens, delivery strategies, and clinical applications for these compounds were examined with an eye toward emerging approaches to address a wide range of medical conditions in the future.

Formulation and Evaluation of Novel Thiolated Intra Pocket Periodontal Composite Membrane of Doxycycline.

Localized intra-pocket, retentive, biodegradable, prolonged release thiolated membrane can provide an improved therapeutic efficacy of doxycycline at the site of action with evading off target side effects. To this end, thiolated chitosan-hyaluronic acid composite polymeric complex next-generation of the periodontal membrane was manufactured by solvent casting method. FTIR spectroscopic analysis displayed successful immobilization of thiol groups on the manufactured thiolated periodontal membrane. Moreover, XRD, DSC, AFM and TGA of the membrane confirmed the compatibility of ingredients and modifications in surface chemistry. The thiolated periodontal film was also investigated in terms of thickness, weight uniformity, water-uptake capacity, drug content, pH, entrapment efficiency, lysozymal degradation and release patterns. Also, mucoadhesion profile was explored on gingival mucosa. The immobilized thiol groups on thiolated chitosan and thiolated hyaluronate were found to be 168 ± 11 µM/g (mean ± SD, n = 3) and 189 ± 8 µM/g (mean ± SD, n = 3) respectively. Swelling capacity of the thiolated periodontal membrane was significantly ∼2-fold higher (p < 0.05) as compared to unmodified membrane. The obtained thiolated membrane depicted 3 -old higher mucoadhesive features as compared to the un-modified membrane. In vitro release kinetics indicated approximately more than 80% prolonged release within 7 days. Mechanical strength of the Thiolated bandage was also significantly ∼2-fold higher (p < 0.05) as compared to unmodified membrane. Ex-vivo retention study revealed enhanced retention of thiolated membrane as compared to unmodified membrane. In-vitro antimicrobial studies demonstrated that thiolated membrane could efficiently kill Porphyromonas gingivalis cells as compared to the native membrane. Moreover, ex-vivo biodegradation results indicated that 90% of the thiolated membrane was biodegradable in 28 days. Based on these findings, thiolated next-generation of the periodontal membrane seems to be promising for periodontitis therapy.

Anti-EGFR antibody conjugated thiol chitosan-layered gold nanoshells for dual-modal imaging-guided cancer combination therapy.

Developing a novel multifunctional theranostic agent for cancer combination therapy has attracted tremendous attention in recent years. In this report, we designed and developed a new multifunctional nanocarrier based on anti-epidermal growth factor receptor antibody-conjugated and paclitaxel loaded-thiol chitosan-layered gold nanoshells (anti-EGFR-PTX-TCS-GNSs) as a theranostic agent for the first time used for fluorescence/photoacoustic dual-modal imaging-guided chemophotothermal synergistic therapy. The resulting anti-EGFR-PTX-TCS-GNSs showed excellent biosafety, biocompatibility, broad near-infrared (NIR) absorbance, photostability, fast and laser irradiation-controllable drug release, and higher targeting efficiency for efficient chemophotothermal combination therapy of cancer under the guidance of photoacoustic imaging (PAI). The combination therapy was investigated in vitro and in vivo, displaying a powerful anticancer efficiency. More importantly, an in vivo experiment of anti-EGFR-PTX-TCS-GNSs with laser irradiation showed heavy damage to the tumor tissue, killing the tumor cells almost completely. Anti-EGFR-PTX-TCS-GNSs also showed a powerful capacity to visualize tumors, and therefore it is considered a new PAI contrast agent for subsequent therapy. Histological analysis and TUNEL assay further showed much more apoptotic cells, confirming the value of anti-EGFR-PTX-TCS-GNSs. Our results provide a new concept and a promising strategy to develop a novel multifunctional nanotheranostic agent for future clinical applications in diagnosis and therapy.

Significant reduction of ischemia-reperfusion cell death in mouse myocardial infarcts using the immediate-acting PrC-210 ROS-scavenger.

Managing myocardial infarction (MI) to reduce cardiac cell death relies primarily on timely reperfusion of the affected coronary site, but reperfusion itself induces cell death through a toxic, ROS-mediated process. In this study, we determined whether the PrC-210 aminothiol ROS-scavenger could prevent ROS-induced damage in post-MI hearts. In a series of both in vitro and in vivo experiments, we show that: (a) in vitro, PrC-210 was the most potent and effective ROS-scavenger when functionally compared to eight of the most commonly studied antioxidants in the MI literature, (b) in vitro PrC-210 ROS-scavenging efficacy was both immediate (seconds) and long-lasting (hours), which would make it effective in both (1) real-time (seconds), as post-MI or cardiac surgery hearts are reperfused with PrC-210-containing blood, and (2) long-term (hours), as hearts are bathed with systemic PrC-210 after MI or surgery, (c) systemic PrC-210 caused a significant 36% reduction of mouse cardiac muscle death following a 45-minute cardiac IR insult; in a striking coincidence, the PrC-210 36% reduction in cardiac muscle death equals the 36% of the MI-induced cardiac cell death estimated 6 years ago by Ovize and colleagues to result from "reperfusion injury," (d) hearts in PrC-210-treated mice performed better than controls after heart attacks when functionally analyzed using echocardiography, and (e) the PrC-210 ROS-scavenging mechanism of action was corroborated by its ability to prevent >85% of the direct, H2O2-induced killing of neonate cardiomyocytes in cell culture. PrC-210 does not cause the nausea, emesis, nor hypotension that preclude clinical use of the WR-1065/amifostine aminothiol. PrC-210 is a highly effective ROS-scavenger that significantly reduces IR injury-associated cardiac cell death.