Human serum albumin nanoparticles loaded with phthalocyanine dyes for potential use in photodynamic therapy of atherosclerotic plaques

Diseases caused by obstruction or rupture of vulnerable plaques in the arterial walls such as cardiovascular infarction or stroke are the leading cause of death in the world. In the present work, we developed human serum albuminnanoparticles loaded by physisorption with zinc phthalocyanine, TT1, mainly used for industrial application as near-infrared photosensitizer and compared these to HSA NPsloaded with the well-known silicone phthalocyanine (Pc4). The use of NIR light allows for better tissue penetration, while the use of nanoparticles permitshigh local concentrations. The particles were characterized and tested for toxicity and stability as well as for their potential use as a contrast agent and NIR photosensitizer for photodynamic therapy in cardiovascular disease. We focused on the distribution of the nanoparticles in RAW264.7macrophage cells and atherosclerotic mice. The nanoparticles had an average size of 120 nm according todynamic light scattering, good loading capacity for zinc phthalocyanine,and satisfying stability in 50% (v/v) fetal bovine serum for 8 hours and in an aqueous environment at 4°C for 4–6 weeks. Under light irradiation we found a high production of singlet oxygen and the products showed no dark toxicity in vitro with macrophages(the target cells in vulnerable plaques),but at a low μg/mL nanoparticleconcentration killed efficiently the macrophagesupon LED illumination. Injection of the contrast agentin atherosclerotic mice led to a visible fluorescence signal of zinc phthalocyaninein the atherosclerotic plaque at 30 minutes and in the lungs with afast clearance of the nanoparticles. Zinc phthalocyanine loaded human serum albumin nanoparticles present an interesting candidate for the visualization and potentially photodynamictreatment of macrophages in atherosclerotic plaquesThe research leading to these results has received funding from FP7-NMP CosmoPHOS-Nano under grant agreement No. 310337. Additional funding was received by the Spanish groups from MINECO (CTQ2017-85393-P) and ERA-NET/MINECO EuroNanoMed2017-191 / PCIN-2017-04

Comparison of four phaC genes from Haloferax mediterranei and their function in different PHBV copolymer biosyntheses in Haloarcula hispanica

Abstract Background The halophilic archaeon Haloferax mediterranei is able to accumulate large amounts of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with high molar fraction of 3-hydroxyvalerate (3HV) from unrelated carbon sources. A Polyhydroxyalkanoate (PHA) synthase composed of two subunits, PhaCHme and PhaEHme, has been identified in this strain, and shown to account for the PHBV biosynthesis. Results With the aid of the genome sequence of Hfx. mediterranei CGMCC 1.2087, three additional phaC genes (designated phaC1, phaC2, and phaC3) were identified, which encoded putative PhaCs. Like PhaCHme (54.8 kDa), PhaC1 (49.7 kDa) and PhaC3 (62.5 kDa) possessed the conserved motifs of type III PHA synthase, which was not observed in PhaC2 (40.4 kDa). Furthermore, the longer C terminus found in the other three PhaCs was also absent in PhaC2. Reverse transcription PCR (RT-PCR) revealed that, among the four genes, only phaC Hme was transcribed under PHA-accumulating conditions in the wild-type strain. However, heterologous coexpression of phaE Hme with each phaC gene in Haloarcula hispanica PHB-1 showed that all PhaCs, except PhaC2, could lead to PHBV accumulation with various 3HV fractions. The three kinds of copolymers were characterized using gel-permeation chromatography (GPC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Their thermal properties changed with the variations in monomer composition as well as the different molecular weights (M w), thus might meet various application requirements. Conclusion We discover three cryptic phaC genes in Hfx. mediterranei, and demonstrate that genetic engineering of these newly identified phaC genes has biotechnological potential for PHBV production with tailor-made material properties. </jats:sec

Recycling mine waste to improve the acid resistance of cement-based composites for underground structures

Cement-based composites are widely used in underground structures for various applications, such as tunnel lining, mine backfilling, and grouting. However, cement-based composites are highly susceptible to attack by sulfuric acid that can be naturally generated around underground structures through a biogenetical and chemical process. This sulfuric acid attack not only significantly reduces the service life of cement-based underground structures, but also leads to an extremely high cost for the maintenance and rehabilitation of the structures. Hence, cement-based composites should be made in a way that is more durable against the sulfuric acid attack. Among all the methods in improving the acid resistance of cement-based composites, the use of pozzolanic materials that can be sourced from local mine waste has shown great potential. The main objective of this thesis is to systematically explore the potential of three types of pozzolanic materials (fly ash, metakaolin and silica fume) that can be recycled from local mine waste in improving the acid resistance of cement-based composites. These three materials were first used as admixtures to replace ordinary Portland cement (OPC) at various dosages. The results showed that the addition of pozzolans in OPC mortar could reasonably improve the acid resistance. In particular, the mixture with 5% silica fume showed the lowest mass loss after sulfuric acid immersion. Then the performance of silica fume and nano-silica was compared. The silica fume was found to be more effective in enhancing the properties of OPC mortar regarding the volume of permeable voids, compressive strength, and acid resistance. After that, the acid resistance of metakaolin-based geopolymers was explored when calcium aluminate cement (CAC) was added. It was found that the addition of CAC drastically improved the acid resistance due to the reduced permeable voids and increased neutralization capacity. Additionally, as fibers are a common component in cement-based materials for underground structures, a green and sustainable nanofiber (cellulose nanocrystals) was introduced in the OPC system to improve the acid resistance. This nanofiber was found to improve the compressive strength and the acid resistance of OPC mortar. At last, based on previous experimental data, a predictive model was proposed to forecast the deterioration of cement-based materials by considering both mixture design and testing conditions. The proposed Bayesian optimized support vector regression model was able to accurately predict the mass change and compressive strength of mortar samples under a sulfuric acid attack. Overall, this thesis explores the potential of pozzolanic materials in improving the acid resistance of cement-based composites. The research findings provide an effective way to mitigate the sulfuric acid attack of cement-based underground structures and an innovative way of recycling mine waste

Recognition of extremophilic archaeal viruses by eukaryotic cells:a promising nanoplatform from the third domain of life

Viruses from the third domain of life, Archaea, exhibit unusual features including extreme stability that allow their survival in harsh environments. In addition, these species have never been reported to integrate into human or any other eukaryotic genomes, and could thus serve for exploration of novel medical nanoplatforms. Here, we selected two archaeal viruses Sulfolobus monocaudavirus 1 (SMV1) and Sulfolobus spindle shaped virus 2 (SSV2) owing to their unique spindle shape, hyperthermostable and acid-resistant nature and studied their interaction with mammalian cells. Accordingly, we followed viral uptake, intracellular trafficking and cell viability in human endothelial cells of brain (hCMEC/D3 cells) and umbilical vein (HUVEC) origin. Whereas SMV1 is efficiently internalized into both types of human cells, SSV2 differentiates between HUVECs and hCMEC/D3 cells, thus opening a path for selective cell targeting. On internalization, both viruses localize to the lysosomal compartments. Neither SMV1, nor SSV2 induced any detrimental effect on cell morphology, plasma membrane and mitochondrial functionality. This is the first study demonstrating recognition of archaeal viruses by eukaryotic cells which provides good basis for future exploration of archaeal viruses in bioengineering and development of multifunctional vectors

Activation of Human Complement System by Dextran-Coated Iron Oxide Nanoparticles Is Not Affected by Dextran/Fe Ratio, Hydroxyl Modifications, and Crosslinking

While having tremendous potential as therapeutic and imaging tools, the clinical use of engineered nanoparticles has been associated with serious safety concerns. Activation of the complement cascade and release of proinflammatory factors C3a and C5a may contribute to infusion-related reactions, whereas opsonization with C3 fragments promotes rapid recognition and clearance of nanomaterials by mononuclear phagocytes. We used dextran-coated superparamagnetic iron oxide nanoparticles (SPIO), which are potent activators of the complement system, to study the role of nanoparticle surface chemistry in inciting complement in human serum. Using complement inhibitors and measuring levels of fluid phase markers (sC5b-9, C5a and Bb), we found that the majority of human complement activation by SPIO is through the alternative pathway (AP). SPIO prepared with high dextran/iron ratio showed some complement activation via calcium-sensitive pathways, but the AP was responsible for the bulk of complement activation and amplification. Activation via the AP required properdin, the positive regulator of the alternative C3bBb convertase. Modification of sugar alcohols of dextran with alkylating, acylating, or crosslinking agents did not overcome complement activation and C3 opsonization. These data demonstrate that human complement activation is independent of dextran modification of SPIO and suggest a crucial role of the AP in immune recognition of nano-assemblies in human serum

A fast-multi-pole accelerated method of fundamental solutions for 2-D broadband scattering of SH waves in an infinite half space

The traditional method of fundamental solution (T-MFS) is known as an effective method for solving the scattering of elastic waves, but the T-MFS is inefficient in solving large-scale or broadband frequency problems. Therefore, in order to improve the performance in efficiency and memory requirement for treating practical complex 2-D broadband scattering problems, a new algorithm of fast multi-pole accelerated method of fundamental solution (FM-MFS) is proposed. Taking the 2-D scattering of SH waves around irregular scatterers in an elastic half-space as an example, the implementation steps are presented in detail. Based on the accuracy and efficiency verification, the FM-MFS is applied to solve the broadband frequency scattering of plane SH waves around group cavities, inclusions, a V-shaped canyon and a semi-elliptical hill. It shows that, compared with T-MFS, the FM-MFS has great advantages in reducing the consumed CPU time and memory for 2-D broadband scattering. Besides, the FM-MFS has excellent adaptability both for broad-frequency and complex-shaped scattering problems

Aluminum impairs rat neural cell mitochondria in vitro.

Exposure to aluminum has been reported to lead to neurotoxicity. Mitochondria are important organelles involved in maintaining cell function. This study investigates the effect of aluminum on mitochondria in rat neural cells. The ultrastructure of mitochondria was observed, and the cell death rate (CDR), reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and 3-[4,5demethyl-2-thiazalyl]-2,-5diphenyl-2H-tetrazolium bromide (MTT) were measured to investigate the effect of aluminum on the mitochondrial structure and its function in neural cells. Results observed from the mitochondrial ultrastructure show that aluminum may impair the mitochondrial membrane and cristae. Increased CDR, enhanced ROS, decreased MMP, and decreased enzyme activity in mitochondria were observed in the Al-exposed neurons (100 – 500 μM). The present study demonstrates that alteration in the mitochondrial structure and function plays an important role in neurotoxic mechanisms induced by aluminum

Pathologic complete response of hepatoid adenocarcinoma of the stomach after chemo-immunotherapy: A rare case report and literature review

BackgroundHepatoid adenocarcinoma of the stomach (HAS) is a highly malignant subtype of gastric carcinoma with specific clinicopathological features and extremely poor prognosis. We present an exceedingly rare case of complete response after chemo-immunotherapy.Case DescriptionA 48-year-old woman with highly elevated serum alpha-fetoprotein (AFP) level was found to have HAS verified by pathological examination based on gastroscopy. Computed tomography scan was done and TNM staging of the tumor was T4aN3aMx. Programmed cell death ligand-1 (PD-L1) immunohistochemistry was performed, revealing a negative PD-L1 expression. Chemo-immunotherapy including oxaliplatin plus S-1 and PD-1 inhibitor terelizumab was given to this patient for 2 months until the serum AFP level decreased from 748.5 to 12.9 ng/mL and the tumor shrank. D2 radical gastrectomy was then performed and histopathology of the resected specimen revealed that the cancerous cells had disappeared. Pathologic complete response (pCR) was achieved and no evidence of recurrence has been found after 1 year of follow-up.ConclusionsWe, for the first time, reported an HAS patient with negative PD-L1 expression who achieved pCR from the combined chemotherapy and immunotherapy. Although no consensus has been reached regarding the therapy, it might provide a potential effective management strategy for HAS patient

C1q-Mediated Complement Activation and C3 Opsonization Trigger Recognition of Stealth Poly(2-methyl-2-oxazoline)-Coated Silica Nanoparticles by Human Phagocytes

Poly(2-methyl-2-oxazoline) (PMOXA) is an alternative promising polymer to poly(ethylene glycol) (PEG) for design and engineering of macrophage-evading nanoparticles (NPs). Although PMOXA-engineered NPs have shown comparable pharmacokinetics and in vivo performance to PEGylated stealth NPs in the murine model, its interaction with elements of the human innate immune system has not been studied. From a translational angle, we studied the interaction of fully characterized PMOXA-coated vinyltriethoxysilane-derived organically modified silica NPs (PMOXA-coated NPs) of approximately 100 nm in diameter with human complement system, blood leukocytes, and macrophages and compared their performance with PEGylated and uncoated NP counterparts. Through detailed immunological and proteomic profiling, we show that PMOXA-coated NPs extensively trigger complement activation in human sera exclusively through the classical pathway. Complement activation is initiated by the sensing molecule C1q, where C1q binds with high affinity (Kd = 11 \ub1 1 nM) to NP surfaces independent of immunoglobulin binding. C1q-mediated complement activation accelerates PMOXA opsonization with the third complement protein (C3) through the amplification loop of the alternative pathway. This promoted NP recognition by human blood leukocytes and monocyte-derived macrophages. The macrophage capture of PMOXA-coated NPs correlates with sera donor variability in complement activation and opsonization but not with other major corona proteins, including clusterin and a wide range of apolipoproteins. In contrast to these observations, PMOXA-coated NPs poorly activated the murine complement system and were marginally recognized by mouse macrophages. These studies provide important insights into compatibility of engineered NPs with elements of the human innate immune system for translational steps

Identification and functional characterization of ABCA4 gene variants in three patients with Stargardt disease or retinitis pigmentosa

IntroductionThe diversity of phenotypes, ranging from inherited retinal dystrophies (such as Stargardt disease 1, cone–rod dystrophy 3, and retinitis pigmentosa 19) to late-onset age-related macular degeneration 2, has been attributed to loss-of-function variants in the ABCA4 gene. In this study, we aimed to identify and analyze potential pathogenic ABCA4 variants in patients with Stargardt disease or retinitis pigmentosa and to explore the impact of an intronic variant (NM_000350.3:c.6386 + 4A&gt;G) on mRNA splicing.MethodsWe enrolled three patients from unrelated families with Stargardt disease or retinitis pigmentosa after comprehensive ophthalmological evaluations were performed. Whole-exome sequencing and Sanger sequencing were applied for mutation screening, focusing on inherited retinal dystrophy-related genes. Additionally, the splicing alteration caused by c.6386 + 4A&gt;G was functionally characterized by a minigene splicing assay.ResultsFive ABCA4 germline variants were detected in three patients: one frameshift, one nonsense, one splicing, and two missense variants. Furthermore, two pathogenic and two likely pathogenic variants and one variant of uncertain significance were determined according to ACMG/AMP and ClinGen sequence variant interpretation (SVI) guidelines. The minigene splicing assay result proved that c.6386 + 4A&gt;G affected the wild-type donor splice-site recognition of intron 46 and yielded a truncated transcript with a 47-bp deletion in exon 46.DiscussionOur study identified two novel ABCA4 variants, expanding the mutational spectrum of the ABCA4 gene in Stargardt disease and retinitis pigmentosa while providing new insights into the molecular pathology of ABCA4 splicing defects