BACKGROUND:To improve the mechanical properties and uncontrolability of degradation of decelularized matrix, wemanufactured genipin cross-linked decelularized annulus fibrosus matrix/chitosan hydrogels as annulus fibrosus tissue-engineereds caffold.
OBJECTIVE:To observe the biocompati bility of annulus fibrosus-derived stem cels with genipin cross-linked decelularized annulus fibrosus matrix/chitosan hydrogels, and the degradation of hydrogels in vivo.
METHODS:Genipin cross-linked decelularized annulus fibrosus matrix/chitosan hydrogels caffoldswere prepared, and the internal structure and hydrophilic property of hydrogels was detected by scanning electron microscopy and contact angle meter, respectively. Afterwards, passage 1 rabbit annulus fibrosus-derived stem cels were seeded on thescaffoldsfor 3 days, cel morphology was observed by inverted immun of luorescence microscopy and scanning electron microscopy after cytoskeleton staining, andadditionaly, curve of cel growth was obtained. In the meanwhile, thescafflodswere transplanted into theintermuscular space of New Zealand white rabbits, and the degradation and inflammatory reaction of the hydrogels were observedafter4 weeks.
RESULTS AND CONCLUSION:The prepared hydrogelsc affoldshowed porous and network structure and the contact angle was (39.94±1.61)°; annulus fibrosus-derived stem cels adhered wel on thescaffold surfacewithafaster growth rate. Furthermore, at 4 weeks after trans plantation, the hydrogelin vivowas degraded, and inflammatory cels appeared. These findings indicate that genipin cross-linked decelularized annulus fibrosus matrix/chitosan hydrogels have good biocompati bility.

BACKGROUND:Endplate cartilage degeneration initiates intervertebral disc degeneration. AMP-activated protein kinase (AMPK) regulates the formation and degradation of cartilage. OBJECTIVE:To explore the role of AMPK in an in vitro natural degeneration model of chondrocytes derived from endplate of rat intervertebral discs. METHODS:Morphology of in vitro subcultured endplate chondrocytes of rat intervertebral discs at passages 0, 2, and 5 were observed under an inverted microscope fol owing cytoskeleton staining. Chondrocyte phenotype, proliferation, and the cartilage marker genes (type II col agen, proteoglycan, SOX-9, matrix metal oproteinase-3 and-13), and AMPK phosphorylation were determined by toluidine blue staining, MTT assay, real-time PCR analysis, and western blot assay, respectively. RESULTS AND CONCLUSION:The altered morphology, decreased proliferation ability, and phenotype loss were observed in chondrocytes with increased passage number. Gene expression of type II col agen, proteoglycan, SOX-9 was significantly decreased;while gene expression of matrix metal oproteinase-3 and-13 was significantly increased in endplate chondrocytes at passage 5 compared with those at passages 0 and 2. AMPK phosphorylation in endplate chondrocytes at passage 5 was significantly decreased. These findings indicate that AMPK phosphorylation is involved in in vitro natural degeneration of chondrocytes derived from the endplate of rat intervertebral discs, and the degeneration of endplate chondrocytes and intervertebral discs can be inhibited through the regulation of AMPK activity.

BACKGROUNDBilateral transpedicular screw fixation in conjunction with interbody fusion is widely used to treat lumbar degenerative diseases; however, there are some disadvantages of using this fixation system. This study comparatively analyzes the results of unilateral and bilateral pedicle screw fixation combined with transforaminal lumbar interbody fusion (TLIF) for one-level lumbar degenerative diseases.

METHODSSixty-six cases with one-level lumbar degenerative diseases were studied. The patients were divided according to surgical approach into a unilateral group (Group A) and a bilateral group (Group B). The patients were evaluated for pain by visual analog scale (VAS) and Oswestry Disability Index (ODI). Operating time, blood loss, duration of hospitalization, and complication rate were also evaluated. Patients were examined at 1, 3, 6, and 12 months postoperatively and every year thereafter.

RESULTSGroup A patients' average preoperative VAS and ODI scores were 7.03 ± 0.98 and (64.22 ± 6.38)%, respectively, significantly decreased to 2.91 ± 0.88 and (14.42±2.08)%, respectively, at the last follow-up (P = 0.000). In Group B, the average preoperative VAS and ODI scores were 6.79 ± 0.86 and (63.22 ± 4.70)%, respectively, significantly decreased to 3.12 ± 0.96 and (14.62 ± 2.08)%, respectively, at the last follow-up (P = 0.000). No significant difference in the duration of hospitalization was found between groups. Operating time and blood loss of (125.9 ± 13.0) minutes and (211.4 ± 28.3) ml, respectively, in Group A were significantly less than (165.2 ± 15.3) minutes and (258.6 ± 18.3) ml, respectively, in Group B (P = 0.000). All patients achieved good bone union and had no pseudarthrosis at the last follow-up.

CONCLUSIONSThere are no clinical differences between unilateral and bilateral pedicle screw fixation combined with TLIF for one-level lumbar degenerative diseases. Unilateral fixation reduces operating time, bleeding, and cost of hospitalization.

Female ; Humans ; Intervertebral Disc Degeneration ; surgery ; Lumbosacral Region ; surgery ; Male ; Middle Aged ; Pedicle Screws