Biocomposites Based on Degradable Materials as Biotechnological Dermal Equivalents

Hybrid tissue-engineered biosystems based on biodegradable polymers of microbiological origin – bacterial cellulose (BC) and a copolymer of 3-hydroxybutyric and 4-hydroxybutyric acid P(3HB/4HB) – were constructed using various methods: 1) the dried BC pellicles were soaked with a 2% P(3HB/4HB) solution in chloroform, kept for 24 h, and dried in a dust-free cabinet until the solvent had completely evaporated; 2) nonwoven membranes were placed into the K. xylinus B-12068 culture, and bacterial cellulose synthesized in it grew under static conditions; 3) powdered cellulose (particle size of 120 μm) was added to a 3% P(3HB/4HB) solution in chloroform and mixed ultrasonically to homogeneity; then, the films were produced by the solvent evaporation technique, at polymer to cellulose ratios of 2:1 and 1:1. Investigation of surface properties of the samples showed an increase in surface hydrophilicity of the composites produced by mixing a solution of P(3HB/4HB) with BC at ratios of 2:1 and 1:1 (the contact angle was 43.9±17.55° and 36.1±0.66°) relative to the starting materials. The physical/mechanical properties of the composites based on P(3HB/4HB) and BC were superior to the properties of the neat materials, and they were largely determined by the methods of production of the composite and the properties of the materials used. Based on the study of surface and physical/mechanical properties of the hybrids, films prepared by casting the polymer solution with BC powder (2:1 and 1:1) followed by solvent evaporation were chosen for studying cell adhesion. These scaffolds were loaded with drugs promoting wound healing (actovegin, solcoseryl) and tested in the culture of fibroblasts derived from the adipose tissue MSCs. The MTT assay showed that the most effective hybrid systems were polymer:bacterial cellulose powder (1:1) samples loaded with actovegin or solcoseryl at a concentration of 5%. Those systems produced a stimulating effect on fibroblasts, and, thus, they can be regarded as promising wound dressings to repair skin defect

A New Method for Treating Burn Wounds Using Targeted Delivery of Medicinal Substances by Magnetic Nanocarrier (Experimental Part)

Проведено экспериментальное исследование на лабораторных животных по изучению эффективности адресной доставки мази левомеколь с помощью магнитных наночастиц и внешнего магнитного поля при термических ожогах. В исследовании принимало участие 20 крыс с двумя очагами ожога. Крысы были разделены на 4 группы: без лечения, терапия с использованием мази левомеколь, лечение с использованием наночастиц, мази левомеколь и внешнего магнитного поля и только магнитотерапии. При гистологическом исследовании на 14-е сутки во всех группах в зоне термического повреждения кожи были отмечены признаки глубокого ожога III и IV степени с распространением некроза на всю глубину дермы и на мышцы. В группе с наночастицами, мазью левомеколь и магнитным полем на фоне уменьшения воспаления отмечалось очаговое появление грануляционной ткани. Таким образом, гистологические исследования ожогового раневого процесса лабораторных животных показали, что использование инновационного биологически активного ранозаживляющего средства на основе наночастиц в сочетании с мазью левомеколь улучшает регенерацию тканей и приводит к ускорению эпителизации, что в целом повышает результаты лечения ожоговой раны. Использование внешнего магнитного поля способствует адресной доставке лечебного нанокомплекса и поддержанию оптимальной концентрации препарата в ранеExperimental studies have been carried out on laboratory animals to investigate the effectiveness of targeted delivery of levomekol ointment using magnetic nanoparticles and an external magnetic field for treatment of thermal burns. The study involved 20 rats, with two burns on each. The rats were divided into 4 groups: untreated; treated with levomekol ointment; treated with levomekol ointment associated with nanoparticles and an external magnetic field; and treated with magnetic field alone. Histological examination was conducted on Day 14, and in all groups, in the thermal burn zone of the skin there were signs of deep three- and four-degree burns with necrosis spread through the dermis, reaching the muscle. In the group with levomekol ointment associated with nanoparticles and magnetic field, inflammation was decreased, and focal granulation tissue formation was observed. Thus, histological studies of the burn wound process in laboratory animals showed that the use of an innovative biologically active wound healing agent based on nanoparticles in combination with the levomecol ointment improved tissue regeneration and accelerated epithelialization, which enhanced the effectiveness of burn wound treatment. The use of an external magnetic field facilitated targeted delivery of the therapeutic nanosystem and maintenance of the optimal concentration of the drug in the woun

Biopolymers for Tissue Engineering

Представлен обзор литературы по применению биополимеров в клеточной и тканевой инженерии. Показаны результаты исследований свойств матриксов, полученных из резорбируемых полимеров полигидроксиалканоатов различного состава, в культуре фибробластовA brief overview of the biopolymers used for cell and tissue engineering is presented. The results of research of matrices made from resorbable polyhydroxyalkanoates with different composition in fibroblast cell line culture are show

Biopolymers for Tissue Engineering

Представлен обзор литературы по применению биополимеров в клеточной и тканевой инженерии. Показаны результаты исследований свойств матриксов, полученных из резорбируемых полимеров полигидроксиалканоатов различного состава, в культуре фибробластовA brief overview of the biopolymers used for cell and tissue engineering is presented. The results of research of matrices made from resorbable polyhydroxyalkanoates with different composition in fibroblast cell line culture are show

Differentiation of Mscs into Osteoblasts on a Porous 3D -Carrier of Poly-3-Hydroxybutyrate

В настоящей статье разработаны и исследованы экспериментальные пористые 3D-носители из разрушаемого природного полимера 3-гидроксимасляной кислоты [П(3ГБ)], предназначенные для восстановления дефектов костной ткани. Способность разработанных 3D-носителей поддерживать адгезию, пролиферацию и направленную дифференцировку клеток в остеобластическом направлении исследована в культуре мультипотентных мезенхимальных стволовых клеток (ММСК), выделенных из костного мозга и жировой ткани. Дифференцировка ММСК в остеобласты подтверждена измерением активности щелочной фосфатазы, экспрессии генов к маркеру костного белка BGP (глутаминовый протеин, участвующий в процессах минерализации), измерением внеклеточных преципитатов солей кальция и фосфораThe study describes preparation and testing of porous 3D implants of natural degradable polymer of 3-hydroxybutyric acid [P(3HB)] for regeneration of bone tissue defects. The ability of the 3D carriers to favor attachment and facilitate proliferation and directed differentiation into osteoblasts of mesenchymal stem cells (MSCs) was studied in the culture of MSCs isolated from bone marrow and adipose tissue. MSC differentiation into osteoblasts was confirmed by measurements of the activity of alkaline phosphatase, gene expression of the marker of bone protein BGP (glutamic protein participating in mineralization) and measurements of intracellular precipitates of calcium and phosphorus salt

Свойства и биосовместимость смесей поли-3-гидроксибутирата-3-гидроксивалерата с поли-ε-капролактоном

Blends consisting of the poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) copolymer and poly- ε-caprolactone (PCL) were used to prepare polymer films by casting solution technique. The structure and physical-mechanical, and biological properties of the films were examined as influenced by the ratios of the blend components. The microstructure of the films was determined by the dominant component: the films had porous surface if the percentage of PHBV was higher than that of PCL and were relatively smooth if the dominant component was PCL. The highest elongation at break (190-368 %) was exhibited by the films prepared from the blends containing 5-25 % PHBV; at 25 % PHBV, local maxima of tensile strength (16 MPa) and Young’s modulus (529 MPa) were observed. Biocompatibility of the films prepared from the blends was studied in the culture of NIH 3T3 mouse fibroblast cells. Results of SEM and DAPI staining, determination of the number of attached cells, and MTT assay showed the absence of cytotoxic effects and high cell adhesion and proliferation, which in some cases were higher than on films prepared from pure PHBV and PCL. Thus, PHBV/PCL blends are suitable materials for constructing cell scaffolds for tissue engineering and other reconstructive technologiesСмеси, состоящие из сополимера поли-3-гидроксибутирата-3-гидроксивалерата (ПГБВ) и поли-ε-капролактона (ПКЛ), были использованы для получения полимерных пленок методом испарения из раствора. Исследованы структура, физико-механические и биологические свойства пленок в зависимости от соотношения компонентов смеси. Микроструктура пленок определялась преобладающим компонентом: пленки имели пористую поверхность, если содержание ПГБВ было выше, чем ПКЛ, и относительно гладкими при преобладании ПКЛ. Наибольшее значение удлинения на разрыв (190-368 %) отмечалось для пленок, полученных из смесей с содержанием 5-25 % ПГБВ; при 25 % ПГБВ наблюдались локальные максимумы предела прочности на разрыв (16 МПа) и модуля Юнга (529 МПа). Биосовместимость полученных из смесей пленок была изучена в культуре фибробластов мыши линии NIH 3T3. Результаты растровой электронной микроскопии, окрашивания DAPI, определения численности прикрепленных клеток и MTT-тест показали отсутствие цитотоксических эффектов и высокий уровень адгезии и пролиферации клеток, в ряде случаев превосходившие соответствующие значения для пленок, приготовленных из чистых ПГБВ и ПКЛ. Таким образом, смеси ПГБВ/ПКЛ являются материалами, подходящими для конструирования клеточных матриксов для тканевой инженерии и других реконструктивных технологи

Biocomposites Based on Degradable Materials as Biotechnological Dermal Equivalents

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.Hybrid tissue-engineered biosystems based on biodegradable polymers of microbiological origin – bacterial cellulose (BC) and a copolymer of 3-hydroxybutyric and 4-hydroxybutyric acid P(3HB/4HB) – were constructed using various methods: 1) the dried BC pellicles were soaked with a 2% P(3HB/4HB) solution in chloroform, kept for 24 h, and dried in a dust-free cabinet until the solvent had completely evaporated; 2) nonwoven membranes were placed into the K. xylinus B-12068 culture, and bacterial cellulose synthesized in it grew under static conditions; 3) powdered cellulose (particle size of 120 μm) was added to a 3% P(3HB/4HB) solution in chloroform and mixed ultrasonically to homogeneity; then, the films were produced by the solvent evaporation technique, at polymer to cellulose ratios of 2:1 and 1:1. Investigation of surface properties of the samples showed an increase in surface hydrophilicity of the composites produced by mixing a solution of P(3HB/4HB) with BC at ratios of 2:1 and 1:1 (the contact angle was 43.9±17.55° and 36.1±0.66°) relative to the starting materials. The physical/mechanical properties of the composites based on P(3HB/4HB) and BC were superior to the properties of the neat materials, and they were largely determined by the methods of production of the composite and the properties of the materials used. Based on the study of surface and physical/mechanical properties of the hybrids, films prepared by casting the polymer solution with BC powder (2:1 and 1:1) followed by solvent evaporation were chosen for studying cell adhesion. These scaffolds were loaded with drugs promoting wound healing (actovegin, solcoseryl) and tested in the culture of fibroblasts derived from the adipose tissue MSCs. The MTT assay showed that the most effective hybrid systems were polymer:bacterial cellulose powder (1:1) samples loaded with actovegin or solcoseryl at a concentration of 5%. Those systems produced a stimulating effect on fibroblasts, and, thus, they can be regarded as promising wound dressings to repair skin defects

Obtaining and Investigation of Polymer Compositions Based on Poly-3-Hydroxybutyrate

Изучены морфология, поверхностные свойства и биосовместимость пленок, полученных из смесей поли-3-гидроксибутирата с поли-ε-капролактоном, поли-DL-лактидом, полиэтиленгликолем и крахмалом. С использованием электронной микроскопии выявлены различия микроструктуры поверхности пленок: у композитов П(3ГБ) с ПЭГ и ПКЛ формируется более крупнопористая поверхность по сравнению с чистым П(3ГБ). Добавление ПЭГ приводило к существенному возрастанию гидрофильности поверхности. В культуре фибробластов мыши NIH 3T3 отмечено отсутствие цитотоксического действия, наличие адгезии и пролиферации клеток. Таким образом, показана биосовместимость исследованных композитов и их пригодность для получения полимерных изделий для клеточных технологийThe morphology, surface properties and biocompatibility of mixtures of poly-3-hydroxybutyrate with poly-ε-caprolactone, poly-DL-lactide, polyethylene glycol and starch were studied. Differences in the film surface microstructure were revealed using electron microscopy: composites of P(3HB) with PEG and PCL had a more coarse-pored surface compared to the pure P(3HB). Addition of PEG led to a significant increase in surface hydrophilicity. In the culture of mouse NIH 3T3 fibroblasts the following effects were observed: the absence of cytotoxic effect, the presence of cell adhesion and proliferation. Thus, the biocompatibility of the studied composites and their suitability for production of polymer products for cellular technologies was show

Differentiation of Mscs into Osteoblasts on a Porous 3D -Carrier of Poly-3-Hydroxybutyrate

В настоящей статье разработаны и исследованы экспериментальные пористые 3D-носители из разрушаемого природного полимера 3-гидроксимасляной кислоты [П(3ГБ)], предназначенные для восстановления дефектов костной ткани. Способность разработанных 3D-носителей поддерживать адгезию, пролиферацию и направленную дифференцировку клеток в остеобластическом направлении исследована в культуре мультипотентных мезенхимальных стволовых клеток (ММСК), выделенных из костного мозга и жировой ткани. Дифференцировка ММСК в остеобласты подтверждена измерением активности щелочной фосфатазы, экспрессии генов к маркеру костного белка BGP (глутаминовый протеин, участвующий в процессах минерализации), измерением внеклеточных преципитатов солей кальция и фосфораThe study describes preparation and testing of porous 3D implants of natural degradable polymer of 3-hydroxybutyric acid [P(3HB)] for regeneration of bone tissue defects. The ability of the 3D carriers to favor attachment and facilitate proliferation and directed differentiation into osteoblasts of mesenchymal stem cells (MSCs) was studied in the culture of MSCs isolated from bone marrow and adipose tissue. MSC differentiation into osteoblasts was confirmed by measurements of the activity of alkaline phosphatase, gene expression of the marker of bone protein BGP (glutamic protein participating in mineralization) and measurements of intracellular precipitates of calcium and phosphorus salt