Novel Biodegradable Polymeric Microparticles Facilitate Scarless Wound Healing by Promoting Re-epithelialization and Inhibiting Fibrosis

Despite decades of research, the goal of achieving scarless wound healing remains elusive. One of the approaches, treatment with polymeric microcarriers, was shown to promote tissue regeneration in various in vitro models of wound healing. The in vivo effects of such an approach are attributed to transferred cells with polymeric microparticles functioning merely as inert scaffolds. We aimed to establish a bioactive biopolymer carrier that would promote would healing and inhibit scar formation in the murine model of deep skin wounds. Here we characterize two candidate types of microparticles based on fibroin/gelatin or spidroin and show that both types increase re-epithelialization rate and inhibit scar formation during skin wound healing. Interestingly, the effects of these microparticles on inflammatory gene expression and cytokine production by macrophages, fibroblasts, and keratinocytes are distinct. Both types of microparticles, as well as their soluble derivatives, fibroin and spidroin, significantly reduced the expression of profibrotic factors Fgf2 and Ctgf in mouse embryonic fibroblasts. However, only fibroin/gelatin microparticles induced transient inflammatory gene expression and cytokine production leading to an influx of inflammatory Ly6C+ myeloid cells to the injection site. The ability of microparticle carriers of equal proregenerative potential to induce inflammatory response may allow their subsequent adaptation to treatment of wounds with different bioburden and fibrotic content

Перспектива применения биогенных квантовых точек наночастиц сульфидов серебра, кадмия и цинка для создания полимерных бионанокомпозитных материалов

The possibility of applying silver, cadmium and zinc sulfide nanoparticles (npAg2S, npCdS and npZnS) obtained using Shewanella oneidensis MR-1 and Bacillus subtilis 168 bacterial cultures for the creation of a new class of polymeric bionanocomposite materials was investigated. Biogenic nanoparticles obtained in aqueous solutions of the corresponding salts in the presence of various types of microorganisms are characterized by the presence of protein molecules on their surface. The molecules composition is determined by the bacterial culture. Proteins stabilize them and allow the nanoparticles to covalently join the active groups of polymeric carriers. Aminated chloromethylated polystyrene microspheres, as well as ion-exchange resins of various types, were used as polymeric matrices. Analysis of interaction with them can be used as a method for studying the properties of biogenic nanoparticles of metal sulfides for subsequent successful selection of a polymeric carrier. The immobilization of biogenic nanoparticles of metal sulfides onto the surface of aminated chloromethylated polystyrene microspheres was found to depend on the level of stability of aqueous nanoparticle suspensions and is determined by the negative charge of biogenic npAg2S, npCdS and npZnS, which suggests covalent binding and the electrostatic interaction of the components in the composition of the polymer bionanocomposite. A comparative analysis of the parameters of nanoparticles depending on the strain used in the biosynthesis was carried out. Analysis of the main physicochemical characteristics of npCdS and npZnS showed that the small size of nanoparticles (npCdS - 5 nm, npZnS - up to 2 nm) and the presence of luminescence peaks at wavelengths less than 400 nm classify them in the blue region of the fluorescence spectrum and identify them as quantum dots. Thus, the possibility of introducing fluorescent quantum dots of nanoparticles of metal sulfides of biogenic origin into various polymeric matrices has been demonstrated, which contributes to the expansion of the horizons for using a new class of nanoparticles to create polymeric bionanocomposites.Исследована возможность применения наночастиц сульфида серебра, кадмия и цинка (npAg2S, npCdS и npZnS), полученных с использованием бактериальных культур Shewanella oneidensis MR-1 и Bacillus subtilis 168, для создания нового класса полимерных бионанокомпозитных материалов. Биогенные наночастицы, полученные в водных растворах соответствующих солей в присутствии различных типов микроорганизмов, характеризуются наличием на их поверхности белковых молекул, состав которых определяется бактериальной культурой. Белки стабилизируют наночастицы и позволяют им ковалентно присоединяться к активным группам полимерных носителей. В качестве полимерных матриц использовали аминированные хлорм,етилирован-ные полистирольные микросферы, а также ионообменные смолы различных типов. Анализ взаилюдействия с ними люжет быть использован в качестве лъетода изучения свойств биогенных наночастиц сульфидов металлов для последующего успешного выбора полимерного носителя. Установлено, что иммобилизация биогенных наночастиц сульфидов металлов на поверхности аминированных хлорметилированных полистирольных микросфер зависит от уровня стабильности водных суспензий наночастиц и определяется отрицательным зарядом биогенных npAg2S, npCdS и npZnS, что предполагает ковалентное связывание и электростатическое взаимодействие компонентов в составе полимерного бионанокомпозита. Проведен сравнительный анализ параметров наночастиц в зависимости от штамма, используемого в биосинтезе. Анализ основных физико-химических характеристик npCdS и npZnS показал, что небольшие размеры наночастиц (npCdS - 5 нм, npZnS - до 2 нм) и наличие люминесцентных пиков на длинах волн менее 400 нм, что относит их к синей области спектра флуоресценции, позволяет классифицировать их как квантовые точки. Таким образом, была продемонстрирована возможность введения флуоресцентных квантовых точек наночастиц сульфидов металлов биогенного происхождения в различные полимерные матрицы, что способствует расширению горизонтов использования нового класса наночастиц для создания полимерных бионанокомпозитов

Engineering Escherichia coli for Efficient Aerobic Conversion of Glucose to Malic Acid through the Modified Oxidative TCA Cycle

Malic acid is a versatile building-block chemical that can serve as a precursor of numerous valuable products, including food additives, pharmaceuticals, and biodegradable plastics. Despite the present petrochemical synthesis, malic acid, being an intermediate of the TCA cycle of a variety of living organisms, can also be produced from renewable carbon sources using wild-type and engineered microbial strains. In the current study, Escherichia coli was engineered for efficient aerobic conversion of glucose to malic acid through the modified oxidative TCA cycle resembling that of myco- and cyanobacteria and implying channelling of 2-ketoglutarate towards succinic acid via succinate semialdehyde formation. The formation of succinate semialdehyde was enabled in the core strain MAL 0 (∆ackA-pta, ∆poxB, ∆ldhA, ∆adhE, ∆ptsG, PL-glk, Ptac-galP, ∆aceBAK, ∆glcB) by the expression of Mycobacterium tuberculosis kgd gene. The secretion of malic acid by the strain was ensured, resulting from the deletion of the mdh, maeA, maeB, and mqo genes. The Bacillus subtilis pycA gene was expressed in the strain to allow pyruvate to oxaloacetate conversion. The corresponding recombinant was able to synthesise malic acid from glucose aerobically with a yield of 0.65 mol/mol. The yield was improved by the derepression in the strain of the electron transfer chain and succinate dehydrogenase due to the enforcement of ATP hydrolysis and reached 0.94 mol/mol, amounting to 94% of the theoretical maximum. The implemented strategy offers the potential for the development of highly efficient strains and processes of bio-based malic acid production

Degradation of polycyclic and halogenated aromatic compounds by Rhodococcus and Arthrobacter species

Schmitz A, Fiedler J, Grund E, Denecke B, Eichenlaub R, Gartemann K-H. Degradation of polycyclic and halogenated aromatic compounds by Rhodococcus and Arthrobacter species. In: Debabov VG, Dudnik YV, Danilenko VN, eds. The Biology of Actinomycetes. Proc. of the 9th Intern. Symp. on the Biology of the Actinomycetes (Moscow, July 1994). New York: Allerton Press; 1995: 150-154

Prospects of Applying Biogenic Quantum Dots of Silver, Cadmium and Zinc Sulfides Nanoparticles to Create Polymeric Bionanocomposite Materials

The possibility of applying silver, cadmium and zinc sulfide nanoparticles (npAg2S, npCdS and npZnS) obtained using Shewanella oneidensis MR-1 and Bacillus subtilis 168 bacterial cultures for the creation of a new class of polymeric bionanocomposite materials was investigated. Biogenic nanoparticles obtained in aqueous solutions of the corresponding salts in the presence of various types of microorganisms are characterized by the presence of protein molecules on their surface. The molecules composition is determined by the bacterial culture. Proteins stabilize them and allow the nanoparticles to covalently join the active groups of polymeric carriers. Aminated chloromethylated polystyrene microspheres, as well as ion-exchange resins of various types, were used as polymeric matrices. Analysis of interaction with them can be used as a method for studying the properties of biogenic nanoparticles of metal sulfides for subsequent successful selection of a polymeric carrier. The immobilization of biogenic nanoparticles of metal sulfides onto the surface of aminated chloromethylated polystyrene microspheres was found to depend on the level of stability of aqueous nanoparticle suspensions and is determined by the negative charge of biogenic npAg2S, npCdS and npZnS, which suggests covalent binding and the electrostatic interaction of the components in the composition of the polymer bionanocomposite. A comparative analysis of the parameters of nanoparticles depending on the strain used in the biosynthesis was carried out. Analysis of the main physicochemical characteristics of npCdS and npZnS showed that the small size of nanoparticles (npCdS - 5 nm, npZnS - up to 2 nm) and the presence of luminescence peaks at wavelengths less than 400 nm classify them in the blue region of the fluorescence spectrum and identify them as quantum dots. Thus, the possibility of introducing fluorescent quantum dots of nanoparticles of metal sulfides of biogenic origin into various polymeric matrices has been demonstrated, which contributes to the expansion of the horizons for using a new class of nanoparticles to create polymeric bionanocomposites