Contribution to the Study of Fungal Strains Contaminating Peanut Pastes in Bangui (Central African Republic)

Introduction: Peanut pastes are food products resulting from artisanal or industrial processing, used in cooking in Africa in general and in Central African Republic in particular. These peanut pastes are often contaminated by molds and filamentous fungi involved in the degradation of hygienic and organoleptic or even toxicological quality. This study aims to determine the epidemiological profile of molds contaminating peanut pastes sold on the Central African market. Methodology: This was a cross-sectional study carried out from June to September 2023. Samples of peanut pastes sold on Central African market were taken and analyzed at the National Laboratory of Clinical Biology and Public Health using the conventional microbiology method according to ISO 7954 standards. The data obtained were collected in the ODK 2023.3.1 application and analyzed with the Epi Info 7 software. A multivariate analysis by logistic regression, Ficher’s exact test, and chi2 at the 5% threshold (p Penicillium sp.;11.25% of Mucor sp.;10.63% of Aspergillus terrei;3.13% of Aspergillus niger;1.25% of Aspergillus medullans;28.13% of Aspergillus flavus;2.50% of Aspergillus fumigatus. Peanut pastes stored beyond three days were more contaminated (94.19%). Conclusion: The results of this study made it possible to highlight strains of mold that impact the hygienic and organoleptic quality of peanut pastes sold at the Central African market. Most of the isolated strains were the Aspergillus flavus species which is recognized by its toxigenic effects. This species is much more incriminated in the contamination of foodstuffs with the production of the toxin which causes underlying pulmonary pathologies in humans.

Toxicological Study of the Hydroalcoholic Extract of a Recipe of Three Plants Used in Traditional Togolese Medicine

This work consisted of assessing the toxicity of a recipe of three plants used in traditional Togolese medicine. Acute and sub-acute toxicity was assessed according to OECD chemical test guidelines n˚423 dated December 17, 2001 and n˚407 dated October 3, 2008 respectively. Cytotoxicity was assessed using the 3-(4,5-dimethylthiazolyl-2-yl-2,5-diphenyltetrazolium bromide (MTT) test. No significant toxicity was observed after 14 and 28 days, although a dose-dependent decrease in creatinemia was observed in male rats (the recipe to be used to moderate creatinine levels). Cytotoxicity was without effect on NCM 365 cells. The results obtained justify the use of the recipe in traditional medicine.

Platelet-based bioactive systems guided precision targeting and immune regulation for cancer therapy

The antitumor effects of conventional drug carriers are often attenuated and limited in application by biological barriers associated with tumor heterogeneity and resistance brought about by low tumor immunogenicity.With the rapid development of nanotechnology,naturally derived bioactive materials,and live cell carriers,a promising strategy emerges for targeting the tumor microenvironment(TME)for precision cancer therapy.The unique injury-targeting properties of platelets can significantly extend functional activity,which cannot be achieved with conventional nanocarriers.In this review,three strategies based on platelet-engineered materials are systematically described,namely nanoparticles for platelet membrane camouflage,engineered activated platelets,and targeted-platelets nanosystems.Platelet-based nanomaterials can effectively coordinate local and distant tumor-host crosstalk with controlled active tumor site recognition and killing effects due to the presence of specific membrane proteins on the surface and the self-secretion of a large number of particles.Further advances in platelets for effectively overcoming biological barriers and reducing immune resistance in cancer immunotherapy applications will be discussed in future clinical practice.This review provides an overview of recent research advances in platelet-based bioactive material-directed immunotherapy and chemotherapy to inform future antitumor combination therapies.

Remodel the perifollicular microenvironment via Minoxidil-loaded microneedle patch and cold atmospheric plasma for treating androgenetic alopecia

Androgenetic alopecia(AGA)is a chronic and progressive form of hair loss characterized by vascular degeneration in the perifollicular microenvironment,leading to cell apoptosis and eventual loss of hair follicles(HFs).Traditional therapeutic formulations,such as Minoxidil(MXD)tincture,have limitations in reshaping the perifollicular microenvironment and exhibit limited effectiveness.Here,we report a multi-synergistic therapeutic platform for high-performance hair regeneration therapy.The platform combines microneedle(MN)patches loaded with MXD-encapsulated nanostructured lipid carriers(MXD-NLC-MNs)and cold atmospheric plasma(CAP).The MNs’mechanical strength enables efficient transdermal delivery of MXD to the targeted dermal papilla cells,promoting cell proliferation.Furthermore,in collaboration with MXD,the mechanical stimulation exerted by MN application synergistically upregulates the expression of vascular endothelial growth factor,leading to neoangiogenesis.Meanwhile,the transient microchannels in the skin created by MNs facilitate the transdermal delivery of CAPgenerated nitric oxide(NO)to the sites of HF lesions,whereby the synergistic interaction between MXD and NO boosts perifollicular vasodilation.Consequently,the perifollicular microenvironment can be effectively reshaped to accelerate hair regeneration in AGA murine models.This multi-synergistic combination therapy strategy would hold great promise for effectively treating AGA and promoting hair regrowth.

Two-color emissive AIEgens with anti-Kasha property for dual-organelle imaging and phototherapy

Despite the rapid development of probes for targeting single organelle, the construction of robust dual-organelle targeting probes with multicolor emission was rarely reported. Herein, two dual-emissive aggregation-induced emission luminogens(AIEgens)with donor-π-acceptor structures were designed and synthesized, namely QT-1 and QF-2. Both two AIEgens exhibited excitation wavelength-dependence defying the Kasha's rule, and could stain lipid droplets(LDs) and mitochondria in blue and red fluorescence, respectively. Moreover, thanks to the near-infrared emission and abundant reactive oxygen species(ROS) generation efficiency of QT-1, it was chosen as a photodynamic therapy agent to selectively kill cancer cells from normal cells. Upon light irradiation, an obvious decrease of mitochondrial membrane potential(MMP) and serious change of mitochondrial shape in cells were observed, which corresponded to the efficient inhibition of tumor growth in vivo. This work afforded a promising strategy for the construction of multicolor emission by tuning anti-Kasha behaviors and expanding their application in dualorganelle targeting-based phototheranostics.

Regulation of HMGB1 release by infl ammasomes

High mobility group box 1(HMGB1)is an evolutionarily conserved non-histone chromatin-binding protein.During infection or injury,activated immune cells and damaged cells release HMGB1 into the extracellular space,where HMGB1 functions as a proinflammatory mediator and contributes importantly to the pathogenesis of inflammatory diseases.Recent studies reveal that infl ammasomes,intracellular protein complexes,critically regulate HMGB1 release from activated immune cells in response to a variety of exogenous and endogenous danger signals.Double stranded RNA dependent kinase(PKR),an intracellular danger-sensing molecule,physically interacts with inflammasome components and is important for infl ammasome activation and HMGB1 release.Together,these studies not only unravel novel mechanisms of HMGB1 release during infl ammation,but also provide potential therapeutic targets to treat HMGB1-related infl ammatory diseases.

One-shot method for purification of multiple natural amelogenin isoforms

Amelogenin isoforms constitute the predominant component in the enamel matrix and each amelogenin isoform executes unique role in the enamel biomineralization process. Enamel matrix derivative enriching amelogenin isoforms have also hioactive property for tissue regeneration. Despite the development of recombinant protein technology that has greatly forwarded the understanding ofamelogenin properties, substantial evidences have revealed biochemical and functional difference between natural amelogenins and their recombinant form. To facilitate the study of enamel formation mechanism, more facile methodology to purify multiple natural amelogenin isoforms is pursued. Here we developed an effective one-shot method via reverse phase high-performance liquid chromatography （RP-HPLC） to purify various amelogenin isoforms from pig-derived amelogenin complex. A thorough process of chromatographic condition establishment including sample analysis on analytical scale and chromatographic condition design on preparative scale was described. Three representative amelogenin isoforms （TRAP, P148, P173） were isolated in one step and their purity was confirmed by matrix-assisted laser desorption/ionization time of flight mass spectrometry （MALDI-TOF-MS） and high resolution mass spectrometry.

Controllable Protein Adsorption and Bacterial Adhesion on Polypyrrole Nanocone Arrays

In this research, polypyrrole nanocone arrays doped with β-Naphthalene sulphonic acid （PPy-NSA） were built. This film was expected to control protein adsorption and bacterial adhesion by potential-induced reversibly redox. The scanning Kelvin probe microscopy （SKPM） and surface contact angles （SCA） tests suggested that the surface potential and wettability of PPy-NSA nanocone arrays could be controlled by simply controlling its redox property via applying potential. The controllable surface potential and wettability in return controlled the adsorption of protein and adhesion of bacteria. The proposed material might find application in the preparation of smart biomaterial surfaces that can regulate proteins and bacterial adhesion by a simple potential switching.

Incorporating catechol into electroactive polypyrrole nanowires on titanium to promote hydroxyapatite formation

To improve the osteointegration property of biomedical titanium,nano-architectured electroactive coating was synthesized through the electrochemical polymerization of dopamine and pyrrole.The highly binding affinity of Ca2t to the catechol moiety of doped dopamine enabled efficient interaction between polypyrrole/polydopamine nanowires and mineral ions.The results indicate that the PPy/PDA nanowires preserved its efficient electro-activity and accelerated the hydroxyapatite deposition in a simulated body fluid.The PPy/PDA nanowires coating could be applied to promote the osteointegration of titanium implant.

Controlling the strontium-doping in calcium phosphate microcapsules through yeastregulated biomimetic mineralization

Yeast cells have controllable biosorption on metallic ions during metabolism.However,few studies were dedicated to using yeast-regulated biomimetic mineralization process to control the strontium-doped positions in calcium phosphate microcapsules.In this study,the yeast cells were allowed to pre-adsorb strontium ions metabolically and then served as sacrificing template for the precipitation and calcination of mineral shell.The pre-adsorption enabled the microorganism to enrich of strontium ions into the inner part of the microcapsules,which ensured a slow-release profile of the trace element from the microcapsule.The co-culture with human marrow stromal cells showed that gene expressions of alkaline phosphatase and Collagen-I were promoted.The promotion of osteogenic differentiation was further confirmed in the 3D culture of cell-material complexes.The strategy using living microorganism as‘smart doping apparatus’to control incorporation of trace element into calcium phosphate paved a pathway to new functional materials for hard tissue regeneration.

Thermal and Magnetic Dual-Responsive Catheter-Assisted Shape Memory Microrobots for Multistage Vascular Embolization

Catheters navigating through complex vessels,such as sharp turns or multiple U-turns,remain challenging for vascular embolization.Here,we propose a novel multistage vascular embolization strategy for hard-to-reach vessels that releases untethered swimming shape-memory magnetic microrobots(SMMs)from the prior catheter to the vessel bifurcation.SMMs,made of organo-gel with magnetic particles,ensure biocompatibility,radiopacity,thrombosis,and fast thermal and magnetic responses.An SMM is initially a linear shape with a 0.5-mm diameter at 20°C inserted in a catheter.It transforms into a predetermined helix within 2 s at 38°C blood temperature after being pushed out of the catheter into the blood.SMMs enable agile swimming in confined and tortuous vessels and can swim upstream using helical propulsion with rotating magnetic fields.Moreover,we validated this multistage vascular embolization in living rabbits,completing 100-cm travel and renal artery embolization in 2 min.After 4 weeks,the SMMs maintained the embolic position,and the kidney volume decreased by 36%.