Polymeric Multilayers that Contain Silver Nanoparticles can be Stamped onto Biological Tissues to Provide Antibacterial Activity

The design of polyelectrolyte multilayers (PEMs) that can be prefabricated on an elastomeric stamp and mechanically transferred onto biomedically‐relevant soft materials, including medical‐grade silicone elastomers (E’～450–1500 kPa; E’‐elastic modulus) and the dermis of cadaver skin (E’～200–600 kPa), is reported. Whereas initial attempts to stamp PEMs formed from poly(allylamine hydrochloride) and poly(acrylic acid) resulted in minimal transfer onto soft materials, we report that integration of micrometer‐sized beads into the PEMs (thicknesses of 6–160 nm) led to their quantitative transfer within 30 seconds of contact at a pressure of ～196 kPa. To demonstrate the utility of this approach, PEMs were impregnated with a range of loadings of silver‐nanoparticles and stamped onto the dermis of human cadaver skin (a wound‐simulant) that was subsequently incubated with bacterial cultures. Skin dermis stamped with PEMs that released 0.25 ± 0.01 μg cm^?2 of silver ions caused a 6 log₁₀ reduction in colony forming units of Staphylococcus epidermidis and Pseudomonas aeruginosa within 12 h. Significantly, this level of silver release is below that which is cytotoxic to NIH 3T3 mouse fibroblast cells. Overall, this study describes a general and facile approach for the functionalization of biomaterial surfaces without subjecting them to potentially deleterious processing conditions.     

Selective Functionalization of Microstructured Surfaces by Laser‐Assisted Particle Transfer

Microcavity arrays represent millions of different reaction compartments to screen, for example, molecular interactions, exogenous factors for cells or enzymatic activity. A novel method is presented to selectively synthesize different compounds in arrays of microcavities with up to 1 000 000 cavities per cm². In this approach, polymer microparticles with embedded pre‐activated monomers are selectively transferred into microcavities with laser radiation. After particle patterning, heating of the particle matrix simultaneously leads to diffusion and coupling of the monomers inside each microcavity separately. This method exhibits flexibility, not only in the choice of compounds, but also in the choice of particle matrix material, which determines the chemical reaction environment. The laser‐assisted selective functionalization of microcavities can be easily combined with the intensively growing number of laser applications for patterning of molecules and cells, which is useful for the development of novel biological assays.     

Fabrication of porous bioactive glass particles by one step sintering

In this study, we reported a facile method to prepare porous bioactive glass microparticles. Porous particles were synthesized by sintering hollow bioactive glass microspheres obtained using a sol-gel co-template technology. The results showed that porous bioactive glass particles possessed a narrow particle size distribution, a relatively porous surface morphology and a hollow structure. It is worth to say that the resulting microparticles present an amorphous structure although the sintering temperature was improved compared to hollow microspheres. The presence of macropore on the shell may provide an efficient method to carry drugs in the hollow cores. Considering the high deposit rate of nanoscale apatite for bioactive glass materials, the porous microparticles should have potential applications in drug and bioactive molecules delivery, in addition to bone tissue regeneration.     

响应面法优化松多酚微粒制备工艺

依据聚电解质自组装原理,利用黑木耳多糖酸性片段（acidic polysaccharide fragments from Auricularia auricula,AAP）和多聚赖氨酸（polylysine,PLL）将松多酚（pine polyphenols from Pinus koraiensis,PPH）包裹为微粒以防止胃环境对多酚类化合物结构的破坏,并且采用响应面试验设计优化制备工艺。通过分析AAP、PLL和PPH的质量浓度3 个因素及其交互作用对PPH微粒包埋率的影响,建立该工艺的二次多项数学模型;利用扫描电镜观察优化后PPH微粒的形貌,并在模拟胃肠道环境中检测多酚释放率。结果显示响应面回归方程拟合性良好,AAP、PLL和PPH的质量浓度对响应值均有显著影响。在AAP质量浓度为900 μg/mL、PPH质量浓度为110 μg/mL以及PLL质量浓度为30 μg/mL的条件下,PPH微粒的包埋率为（86.57±1.07）%,载药量为（24.03±0.81）%。扫描电镜观察表明PPH微粒的直径为200～500 nm,其在模拟胃环境中释放缓慢而在模拟肠道环境中释放迅速。本研究中PPH微粒包埋率的实测值与预测值相比,相对误差较低,说明本研究方法是一种适合PPH微粒制备的方法,并且优化后的PPH微粒可以降低胃环境对PPH的降解。     

阳离子型有机微粒的助留助滤应用研究

探讨了自制的阳离子有机微粒(CPMP)对漂白阔叶木浆、漂白麦草浆和脱墨废纸浆助留助滤作用的影响.结果表明:各种纸料的一次留着率上升随着CPMP用量的增加而上升,随着转速的增加而减少;CPMP对剪切力和pH值大小不太敏感;CPMP对阔叶木浆的助留助滤效果最好,麦草浆次之,对脱墨废纸浆效果最差.     

阳离子型有机微粒的合成及其对阔叶木浆的助留助滤作用

探讨了采用苯乙烯、DADMAC等为原料制备新型结构的阳离子微粒的合成条件，研究了自制的阳离子有机微粒CPMP的特性及其对漂白阔叶木浆助留助滤的作用，并与阴离子聚丙烯酰胺(APAM)、阳离子聚丙烯酰胺(CPAM)进行了比较。     

Platelet-Released Factors: Their Role in Viral Disease and Applications for Extracellular Vesicle (EV) Therapy

Platelets, which are small anuclear cell fragments, play important roles in thrombosis and hemostasis, but also actively release factors that can both suppress and induce viral infections. Platelet-released factors include sCD40L, microvesicles (MVs), and alpha granules that have the capacity to exert either pro-inflammatory or anti-inflammatory effects depending on the virus. These factors are prime targets for use in extracellular vesicle (EV)-based therapy due to their ability to reduce viral infections and exert anti-inflammatory effects. While there are some studies regarding platelet microvesicle-based (PMV-based) therapy, there is still much to learn about PMVs before such therapy can be used. This review provides the background necessary to understand the roles of platelet-released factors, how these factors might be useful in PMV-based therapy, and a critical discussion of current knowledge of platelets and their role in viral diseases.