As an implantable biomaterial, polyetherketoneketone (PEKK) exhibits good mechanical strength but it is biologically inert while tantalum (Ta) possesses outstanding osteogenic bioactivity but has a high density and elastic modulus. Also, silicon nitride (SN) has osteogenic and antibacterial activity. In this study, a microporous surface containing both SN and Ta microparticles on PEKK (STP) exhibiting excellent osteogenic and antibacterial activity was created by sulfonation. Compared with sulfonated PEKK (SPK) without microparticles, the surface properties (roughness, surface energy, hydrophilicity and protein adsorption) of STP significantly increased due to the SN and Ta particles presence on the microporous surface. In addition, STP also exhibited outstanding antibacterial activity, which inhibited bacterial growth
in vitro
and prevented bacterial infection
in vivo
because of the presence of SN particles. Moreover, the microporous surface of STP containing both SN and Ta particles remarkably induced response (e.g., proliferation and differentiation) of rat bone mesenchymal stem (rBMS) cells
in vitro
. Furthermore, STP significantly improved new bone regeneration and osseointegration
in vivo
. Regarding the induction of cellular response
in vitro
and improvement of osseointegration
in vivo
, the microporous surface containing Ta was better than the surface with SN particles. In conclusion, STP with optimized surface properties activated cellular responses
in vitro
, enhanced osseointegration and prevented infection
in vivo
. Therefore, STP possessed the dual biofunctions of excellent osteogenic and antibacterial activity, showing great potential as a bone substitute.
ObjectiveTo observe the relationship between the perihematomal glutamate levels and the blood–brain barrier (BBB) permeability in a rabbit model of intracerebral hemorrhage (ICH).MethodsSeventy-two rabbits were randomly divided into an intracerebral hemorrhage (ICH) model group and a normal control (NC) group, and each group of 36 rabbits was subsequently divided into 6, 12, 18, 24, 48 and 72 h groups (n = 6 each). An ICH model was induced by stereotactic injection of autologous, arterial, non-anticoagulated blood into rabbit basal ganglia. The same procedures were performed in the NC group, but blood was not injected. The rabbits were sacrificed at specific time points after the experiment began depending on their group. Perihematomal brain tissues were collected to determine glutamate levels, BBB permeability and brain water content (BWC).ResultsAll of the assessed parameters were increased 6 hour after blood infusion and continued to gradually increase, peaking at 48 hours. Differences were observed when ICH values were compared with those of the NC group (p < 0.05).ConclusionsPerihematomal glutamate increased significantly after ICH. High levels of glutamate are closely associated with BBB disruption and the brain edema. Therefore, glutamate may play an important role in the pathogenesis of secondary brain injury after (ICH).
To improve the bioperformances
of porous polyetheretherketone (PPK)
for bone repair, silicon nitride-coated PPK (CSNPPK) was prepared
by a method of suspension coating and melt binding. The results revealed
that, as compared with PPK, the surface roughness, compressive strength,
and water absorption of CSNPPK increased, while the pore size and
porosity of CSNPPK exhibited no obvious changes. In addition, the
cellular responses (including attachment, proliferation, and differentiation
as well as osteogenically related gene expressions) of the MC3T3-E1
cells to CSNPPK were remarkably promoted compared with PPK and dense
polyetheretherketone in vitro. Moreover, in the model of rabbit femoral
condyle defects, the results of micro computed tomography and histological
and mechanical evaluation revealed that the ingrowth of new vessels
and bone tissues into CSNPPK was significantly greater than that into
PPK in vivo. Furthermore, the load–displacement and push-out
loads for CSNPPK with bone tissues were higher than for PPK, indicating
good osseointegration. In short, CSNPPK not only promoted vascularization
but also enhanced osteogenesis as well as osseointegration in vivo.
Therefore, it can be suggested that CSNPPK with good biocompatibility,
osteogenic activity, and vascularization might be a promising candidate
as an implant for bone substitute and repair.
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