Chronic low back pain is strongly linked to degeneration of the intervertebral disc (IVD), which currently lacks any targeted treatments. This study explores NPgel, a biomaterial combined with notochordal cells (NC), developmental precursor cells, as a potential solution. NCs, known for anti-catabolic effects on IVD cells, present a promising avenue for regenerating damaged IVD tissue. Bovine IVDs underwent enzymatic degeneration before NPgel (+/- NC) injection. Degenerated bovine IVDs were cultured under biomechanical loading for 21 days. Histology and immunohistochemistry assessed NC survival, phenotype, and matrix production. Within an Background
Methods
IVD degeneration is a major cause of Low back pain. We have previously reported an injectable hydrogel (NPgel), which induces differentiation of human MSCs to disc cells and integrates with NP tissue following injection MSCs were cultured in NP gel under 5% O2 in either: standard culture (DMEM, pH7.4); healthy disc (DMEM, pH7.1); degenerate disc (low glucose DMEM, pH6) or degenerate disc plus IL-1β. Following 4 weeks histological staining and immunohistochemical analysis investigated viability, ECM synthesis and matrix degrading enzyme expression. Here we have shown that viability and NP cell differentiation of MSCs incorporated within NPgel was mostly unaffected by treatment with conditions such as low glucose, low pH and the presence of cytokines, all regarded as key contributors to disc degeneration. In addition, the NPgel was shown to prevent MSCs from displaying a catabolic phenotype with low expression of degradative enzymes, highlighting the potential of NPgel to differentiate hMSCs and protect them from the degenerate disc microenvironment.Purpose of study and background
Methods and Results
We have previously reported the development of injectable hydrogels for potential disc regeneration (NPgel) or bone formation which could be utilized in spinal fusion (Bgel). As there are multiple sources of mesenchymal stem cells (MSCs), this study investigated the incorporation of patient matched hMSCs derived from adipose tissue (AD) and bone marrow (BM) to determine their ability to differentiate within both hydrogel systems under different culture conditions. Human fat pad and bone marrow derived MSCs were isolated from femoral heads of patients undergoing hip replacement surgery for osteoarthritis with informed consent. MSCs were encapsulated into either NPgel or Bgel and cultured for up to 6 weeks in 5% (NPgel) or 21% (Bgel) O2. Histology and immunohistochemistry was utilized to determine phenotype. Both fat and bone marrow derived MSCs, were able to differentiate into both cell lineages. NPgel culture conditions increased expression of matrix components such as collagen II and aggrecan and NP phenotypic markers FOXF1 and PAX1, whereas Bgel induced expression of collagen I and osteopontin, indicative of osteogenic differentiation.Purpose of study and background
Methods and Results
Stem cell therapy has been suggested as a potential regenerative strategy to treat IVD degeneration and GDF6 has been shown to differentiate adipose-derived stem cells (ASCs) into an NP-like phenotype. However, for clinical translation, a delivery system is required to ensure controlled and sustained GDF6 release. This study aimed to investigate the encapsulation of GDF6 inside novel microparticles (MPs) to control delivery and assess the effect of the released GDF6 on NP-like differentiation of human ASCs. GDF6 release from PLGA-PEG-PLGA MPs over 14 days was determined using BCA and ELISA. The effect of MP loading density on collagen gel formation was assessed through SEM and histological staining. ASCs were cultured in collagen hydrogels for 14 days with GDF6 delivered exogenously or via microspheres. ASC differentiation was assessed by qPCR for NP markers, glycosaminoglycan production (DMMB) and immunohistochemistry.Background
Methods
Signalling by growth differentiation factor 6 (GDF6/BMP13) has been implicated in the development and maintenance of healthy NP cell phenotypes and GDF6 mutations are associated with defective vertebral segmentation in Klippel-Feil syndrome. GDF6 may thus represent a promising biologic for treatment of IVD degeneration. This study aimed to investigate the effect of GDF6 in human NP cells and critical signal transduction pathways involved. BMP receptor expression profile of non-degenerate and degenerate human NP cells was determined through western blot, immunofluorescence and qPCR. Phosphorylation statuses of Smad1/5/9 and non-canonical p38 MAPK and Erk1/2 were assessed in the presence/absence of pathway blockers. NP marker and matrix degrading enzyme gene expression was determined by qPCR following GDF6 stimulation. Glycosaminoglycan and collagen production were assessed through DMMB-assay and histochemical staining.Background
Methods
Degeneration of the intervertebral disc (IVD) is a major cause of Low back pain. We have recently reported a novel, injectable liquid L-pNIPAM-co-DMAc hydrogel (NPgel), which promote differentiation of MSCs to nucleus pulposus (NP) cells without the need for additional growth factors. Here, we investigated the behaviour of hMSCs incorporated within the hydrogel injected into NP tissue. hMSCs were injected either alone or within NPgel, into bovine NP tissue explants and maintained at 5% O2 for up to 6wks. Media alone and acellular NPgel were also injected into NP explants to serve as controls. Cell viability was assessed by Caspase 3 immunohistochemistry and the phenotype of injected hMSC was assessed by histology and immunohistochemistry. Mechanical properties were also assessed via dynamic mechanical analysis (DMA).Background
Methods
Non-tuberculous mycobacterial infections pose a significant diagnostic and therapeutic challenge. We report two cases of such infection of the spine in HIV-negative patients who presented with deformity and neurological deficit. The histopathological features in both specimens were diagnostic of tuberculosis. The isolates were identified as
