Neural progenitor cells but not astrocytes respond distally to thoracic spinal cord injury in rat models

Traumatic spinal cord injury （SCI） is a detrimental condition that causes loss of sensory and motor function in an individual. Many complex secondary injury cascades occur after SCI and they offer great potential for therapeutic targeting. In this study, we investigated the response of endogenous neural progenitor cells, astrocytes, and microglia to a localized thoracic SCI throughout the neuroaxis. Twenty-five adult female Sprague-Dawley rats underwent mild-contusion thoracic SCI （n = 9）, sham surgery （n = 8）, or no surgery （n = 8）. Spinal cord and brain tissues were fixed and cut at six regions of the neuroaxis. Immunohistochem- istry showed increased reactivity of neural progenitor cell marker nestin in the central canal at all levels of the spinal cord. Increased reactivity of astrocyte-specific marker glial fibrillary acidic protein was found only at the lesion epicenter. The number of activated microglia was significantly increased at the lesion site, and activated microglia extended to the lumbar enlargement. Phagocytic microglia and macrophages were significantly increased only at the lesion site. There were no changes in nestin, glial fibrillary acidic protein, microglia and macrophage response in the third ventricle of rats subjected to mild-contusion thoracic SCI compared to the sham surgery or no surgery. These findings indicate that neural progenitor cells, astrocytes and microglia respond differently to a localized SCI, presumably due to differences in inflammatory signaling. These different cellular responses may have implications in the way that neural progenitor cells can be manipulated for neuroregeneration after SCI. This needs to be further investigated.

Heavy Metal Remediation in Sludge Compost: Recent Progress

The safe and efficient disposal and utilization of sludge are major issues to be solved in solid waste treatment and environmental protection due to the complex characteristics of sludge and the low rate of innocuous treatments.Composting is a process of decomposing organic matter and transformed low-molecular organic acids into high-molecular humus substances under the action of microorganisms.Although land-use after composting has become an important direction for sludge treatment,heavy metal pollution is still the bottleneck problem restrict-ing land use of sludge compost.Adding zeolite,hydroxyapatite,and other conditioning agents to the composting process affects the concentration or form of some heavy metals and effectively reduces the environmental risk.Lime and phosphorus modifiers change heavy metal speciation in samples,playing a role in decreasing biological availability and mobility.In this study,the effects of sludge composting treatment and conditioning agents on the concentrations and forms of heavy metals are reviewed.This review will provide a theoretical basis to treat heavy metals in sludge composting and lay the foundation for the land utilization and waste recycling of sludge.

Endogenous neural progenitor cells in the repair of the injured spinal cord

Stem cell treatments,and in particular,stem cell transplants have been identified as potential therapeutic strategies for a range of neurodegenerative and acquired conditions of the central nervous system（CNS）.Stem cell transplants are seen as a way of replacing lost neurons,or providing a cellular environment that is more permissible for axon and cell regeneration.

Wet-adhesive materials of oral and maxillofacial region:From design to application

Oral and maxillofacial diseases are a group of high-incidence disorders that affect people’s life quality to a great extent,while the wet and highly movable environment of the related regions brings challenges to traditional therapies.Faced with the obstacles of insufficient adhesive strength and ensuing short drug retention time,conventional oral therapeutic agents often have difficulty in achieving their desired efficacy.Oral and maxillofacial wet-adhesive materials have the advantages of excellent wet environment retention,internal stability,plasticity,and clinical potential,thus have become a significant research direction in the field of oral related disorders healing.In the past decade,the development of oral adhesive materials with good wet adhesion has accelerated based on the chemical molecular interaction,physical interlocking,and biological adhesion mechanisms,including biomimetic-inspired materials,naturally derived polymer–based materials and adhesive electrospun fiber films.These fancy wet-adhesive materials can be used for oral mucosal drug delivery,oral vaccination,wound healing,and bone defects treatments.Despite their numerous novel applications,wet-adhesive materials in stomatology still face unresolved challenges from material and biological aspects.Here,advances in designs of oral and maxillofacial wetadhesive materials are reviewed in terms of design backgrounds,attachment mechanisms,and common classifications.Recent demonstrations of wet-adhesive materials for oral and maxillofacial region medical applications from drug delivery to multifunctional tissue treatments are presented.To conclude,current challenges and prospects on potential applications of oral and maxillofacial wet-adhesive materials are also briefly discussed.