Programmable Building of Radially Gradient Nanofibrous Patches Enables Deployment, Bursting Bearing Capability, and Stem Cell Recruitment
22
Citation
50
Reference
10
Related Paper
Citation Trend
Abstract:
Abstract Fibrous patches capable of withstanding bursting force and recruiting endogenous stem cells are of great demand for wound treatment. A programmable strategy for development of radially gradient nanofibrous patches with rapid deployment property, robust bursting bearing capability, and excellent mesenchymal stem cell (MSC) recruitment capability, is demonstrated. Benefiting from the royal water lily‐like radially branched architecture, the gradient fibrous (GF) patches exhibit fast deployment in aqueous solution (2 s), high bursting strength of 4.6 N, as well as “center‐to‐periphery” gradient immobilization of stromal‐cell‐derived factor 1α (SDF1α). The SDF1α gradient patches direct MSC migration from the periphery to the center along the aligned nanofibers, resulting in a 4.2 times higher migrated cell number and 2.6 times greater maximum migration distance than random fibrous patches with homogenous SDF1α. The gelatin methacryloyl coated GF patches respond to matrix metalloproteinase‐9 for “on‐demand” release of anti‐inflammatory drug diclofenac sodium (DS). Furthermore, repair of the mouse full‐thickness skin incision validates that SDF1α/DS/GF patches are able to provide feasible microenvironment to attenuate inflammation and improve endogenous MSC recruitment, leading to accelerated wound healing. This work may open a new pathway for development of smart tough fibrous patches for stimulating endogenous repair mechanisms during tissue regeneration.Keywords:
Bursting
Bursting
Oscillation (cell signaling)
Cite
Citations (22)
Bursting
Cite
Citations (23)
Bursting
Enteroendocrine cell
Cite
Citations (43)
Bursting
Cite
Citations (0)
Bursting
Oscillation (cell signaling)
Cite
Citations (9)
We describe a novel type of bursting that we observe in simulations of large recurrent networks of biophysically plausible, intrinsically non-bursting neurons. The mechanism responsible for the bursting is a combination of excitatory feedback received from neighbouring neurons, together with an activity-dependent adaptation mechanism that slows down spiking. During the bursting phases, the firing patterns are not repeated and the lengths of the interburst intervals are varying. We develop a simple phenomenological model that captures most qualitative aspects of the observed collective bursting. We compare the parameter range leading to bursting in the phenomenological model, with parameter estimates from cortical anatomy and physiology, and conjecture that the discovered new type of bursting should also be observable in biological neocortical networks.
Bursting
Cite
Citations (5)
1. We tested whether firing characteristics are associated with the onset of bursting in oxytocin cells during suckling. Extracellular electrical activity of paraventricular and supraoptic oxytocin cells was recorded in lactating rats from the beginning of suckling up to the first milk-ejection burst, which occurred either within less than 1 h of suckling (bursting cells) or after injecting facilitatory drugs (non-bursting cells). 2. Significant differences in the distributions of firing rate (using low, intermediate and high categories, < or = 1, 1-3 and > 3 spikes s-1, respectively) of bursting and non-bursting cells were observed during suckling. Thirty minutes after pup application, most bursting cells (56%) had an intermediate firing rate, whereas non-bursting cells had either a low (36%) or high (40%) firing rate. 3. Thirty minutes after applying the pups, probability of bursting was highest for cells firing at 1-4 spikes s-1, and lowest for those firing above 5 spikes s-1. 4. Bursting cells with high initial firing rate decreased their firing rate substantially during suckling while most of those with low initial firing rate showed increases. For non-bursting cells, activity was maintained. 5. There were marked differences in firing rate and its evolution between paired bursting cells. The firing rates for non-bursting cell pairs were similar (mostly either low or high), and remained stable during suckling. 6. In conclusion, we suggest that, as suckling proceeds, probability of bursting is related to the firing rate of oxytocin cells within the whole population, more specifically to the proportion of cells within the animal initially or subsequently displaying a critical firing rate (between 1 and 3 spikes s-1). The firing rates of cells which eventually burst and which are firing outside this range change in a direction which brings them into the preferred range for bursting. 7. We suggest that when bursting occurs unaided, a majority of oxytocin cells fire in the preferred bursting range and facilitate the bursting of cells outside this range. Since such cooperativity does not develop between non-bursting cells, it might be due to centrally released oxytocin.
Bursting
Cite
Citations (68)
Bursting
Dynamics
Cite
Citations (23)
Bursting
Cite
Citations (11)