2 research outputs found
On-Site Formation of Functional Dopaminergic Presynaptic Terminals on Neuroligin-2-Modified Gold-Coated Microspheres
Advancements in neural interface
technologies have enabled the
direct connection of neurons and electronics, facilitating chemical
communication between neural systems and external devices. One promising
approach is a synaptogenesis-involving method, which offers an opportunity
for synaptic signaling between these systems. Janus synapses, one
type of synaptic interface utilizing synaptic cell adhesion molecules
for interface construction, possess unique features that enable the
determination of location, direction of signal flow, and types of
neurotransmitters involved, promoting directional and multifaceted
communication. This study presents the first successful establishment
of a Janus synapse between dopaminergic (DA) neurons and abiotic substrates
by using a neuroligin-2 (NLG2)-mediated synapse-inducing method. NLG2
immobilized on gold-coated microspheres can induce synaptogenesis
upon contact with spatially isolated DA axons. The induced DA Janus
synapses exhibit stable synaptic activities comparable to that of
native synapses over time, suggesting their suitability for application
in neural interfaces. By calling for DA presynaptic organizations,
the NLG2-immobilized abiotic substrate is a promising tool for the
on-site detection of synaptic dopamine release
Anti-inflammatory and Antibacterial Effects of Covalently Attached Biomembrane-Mimic Polymer Grafts on Gore-Tex Implants
Expanded
polytetrafluoroethylene (ePTFE), also known as Gore-Tex,
is widely used as an implantable biomaterial in biomedical applications
because of its favorable mechanical properties and biochemical inertness.
However, infection and inflammation are two major complications with
ePTFE implantations, because pathogenic bacteria can inhabit the microsized
pores, without clearance by host immune cells, and the limited biocompatibility
can induce foreign body reactions. To minimize these complications,
we covalently grafted a biomembrane-mimic polymer, polyÂ(2-methacryloyloxylethyl
phosphorylcholine) (PMPC), by partial defluorination followed by UV-induced
polymerization with cross-linkers on the ePTFE surface. PMPC grafting
greatly reduced serum protein adsorption as well as fibroblast adhesion
on the ePTFE surface. Moreover, the PMPC-grafted ePTFE surface exhibited
a dramatic inhibition of the adhesion and growth of <i>Staphylococcus
aureus</i>, a typical pathogenic bacterium in ePTFE implants,
in the porous network. On the basis of an analysis of immune cells
and inflammation-related factors, i.e., transforming growth factor-β
(TGF-β) and myeloperoxidase (MPO), we confirmed that inflammation
was efficiently alleviated in tissues around PMPC-grafted ePTFE plates
implanted in the backs of rats. Covalent PMPC may be an effective
strategy for promoting anti-inflammatory and antibacterial functions
in ePTFE implants and to reduce side effects in biomedical applications
of ePTFE