Dual-Function Antibacterial Micelle via Self-Assembling Block Copolymers with Various Antibacterial Nanoparticles

Abstract

Antibacterial biomaterials with kill-resist dual functions by combining multiple active components have been constructed, with a final aim at decreasing the incidence of biomaterial-centered infection. Self-assemblies of bactericidal ZnO or Ag−ZnO nanoparticles (NPs) with triblock copolymers, poly(ethylene glycol)-b-poly(3-hydroxybutyrate-co-3-hydroxyvalerate)−poly(ethylene glycol) (PEG−PHBV−PEG), showed a hydrophobic PHBV layer on NPs with PEG segments exposed outside via hydrogen bonding, resulting in long PEG (M w = 2000) aggregation and short PEG (M w = 1000) aggregation, respectively. These nanocomposite aggregations released ZnO or Ag−ZnO rapidly within initial few hours, and about 42−45% of NPs were left in the nanocomposites in deionized water for 16 d to improve the long-term antibacterial activity further. At the concentration below 50 μg/mL, the nanocomposite aggregation was cellcompatible with ATDC5 and showed sterilization rates over 91% against Escherichia coli and 98% against Staphylococcus aureus. Long PEG aggregation showed greater cell proliferation capacity than short PEG aggregation, as well as better bacterial resistance and bactericidal activity against both E. coli and S. aureus. The flexible self-assembling antibacterial NPs with antifouling block copolymers via adjusting the component ratio or the segment length have shown premise in the construction of the dual-function antibacterial materials.

"Teaching Reform of Obstetrics and Gynecology Nursing Course in Higher Vocational Colleges Based on OBE Education Concept from the Perspective of Big Data"

“…We deconstruct and reorganize the curriculum according to the female life cycle and divide the curriculum into five modules. Now take module two pregnancy care as an example to choose the key and difficult points and corresponding teaching strategies (Table 2) [8]. This teaching mode realizes "three highs" of teaching effect, that is, high participation of students, high timeliness of learning process, and high personalization of learning results [9].…”

Аntibacterial inorganic agents: efficiency of using multicomponent systems

“…Многочисленные исследования показали, что включение наночастиц Ag, ZnO, CuO, Fe 2 O 3 в ряд полимерных соединений, в том числе хитозан, целлюлозу, усиливает антимикробные свойства материалов, а также способствует более длительному высвобождению антибактериальных агентов [25,55,59,76]. Среди них, например, наночастицы серебра, закрепленные на биосовместимой нанофибриллированной целлюлозе (NFC) [42], мембраны из бактериальной целлюлозы, нагруженные наночастицами меди или оксида цинка [33,39], гибридное покрытие гидроксиапатит/хитозан/серебро на поверхности титанового имплантата [77], наночастицы Ag-ZnO c триблок-сополимерами PEG-PHBV-PEG [81], полиметилметакрилат/высокомолекулярный поли винилпирролидон/наночастицы серебра [1,7]. В количественном чашечно-суспензионном тесте показано снижение уровня микробной популяции чувствительного и резистентного к гентамицину изолятов S. epidermidis на 3log10 в вытяжках из костного цемента с нанокластерами серебра (антисептик повиаргол) на 292 день эксперимента [1], тогда как стандартный костный цемент с гентамицином оказывает антимикробный эффект не более 56 дней [10], что свидетельствует об эффективности наночастиц серебра в отношении антибиотикорезистентных штаммов микроорганизмов и о пролонгации этого эффекта в присутствии полимера поливинилпирролидона.…”

Smart DEA–QCGM–CNT hydrogels with temperature- and NIR-responsive behavior achieved by the synergy between CNT and QCGM for wound dressing

“…Nanocomposite hydrogels were reported recently by adopting carbon nanotube (CNT) as the additive to enhance the mechanical property of the materials and to endow the hydrogels with excellent NIR stimuli-responsive ability 18,[25][26][27] . On the other hand, the rising incidence of infection by bacteria is another thorny issue in wound treatment [28][29][30][31] . Meanwhile, wound dressings with inherent antibacterial ability represent better performance than broad-spectrum antibiotics in anti-wound infection 28,32 .…”

“…18,[25][26][27] On the other hand, the rising incidence of infection by bacteria is another thorny issue in wound treatment. [28][29][30][31] Meanwhile, wound dressings with inherent antibacterial ability represent better performance than broad-spectrum antibiotics in anti-wound infection. 28,32 Quaternized chitosan (QCS) not only exhibits more positive charges, which endow better antibacterial properties, 33,34 but also exhibits better water solubility, hemostatic properties, and biocompatibility, 35,36 suggesting that it has broader application prospects.…”