Background: The nonpsychotropic phytocannabinoid cannabidiol (CBD) presents itself as a potentially safe and effective anti-inflammatory treatment relative to clinical standards. In this present study, we compare the capacity of CBD to the corticosteroid dexamethasone (Dex) in altering the secreted protein landscape of activated macrophages and speculate upon the mechanism underpinning these alterations. Materials and Methods: Human THP-1 monocytes were differentiated into macrophages (THP-1 derived macrophages [tMACs]), activated with lipopolysaccharide (LPS), and then treated with 5, 10, 25, 50, or 100 lM CBD or 10 lM Dex for 24 h. Following treatment, cytotoxicity of CBD and protein expression levels from culture supernatants and from whole cell lysates were assessed for secreted and intracellular proteins, respectively. Results: High concentration (50 and 100 lM) CBD treatments exhibit a cytotoxic effect on LPS-activated tMACs following the 24-h treatment. Relative to the LPS-activated and untreated control (M[LPS]), both 25 lM CBD and 10 lM Dex reduced expression of pro-inflammatory markers-tumor necrosis factor alpha, interleukin 1 beta, and regulated on activation, normal T cell expressed and secreted (RANTES)-as well as the pleiotropic marker interleukin-6 (IL-6). A similar trend was observed for anti-inflammatory markers interleukin-10 and vascular endothelial growth factor (VEGF). Dex further reduced secreted levels of monocyte chemoattractant protein-1 in addition to suppressing IL-6 and VEGF beyond treatments with CBD. The anti-inflammatory capacity of 25 lM CBD was concurrent with reduction in levels of phosphorylated mammalian target of rapamycin Ser 2448, endothelial nitric oxide synthase, and induction of cyclooxygenase 2 relative to M(LPS). This could suggest that the observed effects on macrophage immune profile may be conferred through inhibition of mammalian target of rapamycin complex 1 and ensuing induction of autophagy. Conclusion: Cumulatively, these data demonstrate cytotoxicity of high concentration CBD treatment. The data reported herein largely agree with other literature demonstrating the anti-inflammatory effects of CBD. However, there is discrepancy within literature surrounding efficacious concentrations and effects of CBD on specific secreted proteins. These data expand upon previous work investigating the effects of CBD on inflammatory protein expression in macrophages, as well as provide insight into the mechanism by which these effects are conferred.

In a material-guided approach, instructive scaffolds that leverage potent chemistries may efficiently promote bone regeneration. A siloxane macromer has been previously shown to impart osteoinductivity and bioactivity when included in poly­(ethylene glycol) diacrylate (PEG-DA) hydrogel scaffolds. Herein, phosphonated-siloxane macromers were evaluated for enhancing the osteogenic potential of siloxane-containing PEG-DA scaffolds. Two macromers were prepared with different phosphonate pendant group concentrations, poly­(diethyl­(2-(propylthio)­ethyl)­phosphonate methylsiloxane) diacrylate (PPMS-DA) and 25%-phosphonated analogue (PPMS-DA 25%). Macroporous, templated scaffolds were prepared by cross-linking these macromers with PEG-DA at varying mol % (15:85, 30:70, and 45:55 PPMS-DA to PEG-DA; 30:70 PPMS-DA 25% to PEG-DA). Other scaffolds were also prepared by combining PEG-DA with PDMS-MA (i.e., no phosphonate) or with vinyl phosphonate (i.e., no siloxane). Scaffold material properties were thoroughly assessed, including pore morphology, hydrophobicity, swelling, modulus, and bioactivity. Scaffolds were cultured with human bone marrow-derived mesenchymal stem cells (normal media) and calcium deposition and protein expression were assessed at 14 and 28 days.

Objective The objective of this study was to compare the effects of hyperosmolar sodium (Na+), lithium (Li+) and potassium (K+) on catabolic and inflammatory osteoarthritis (OA) markers and sulfated glycosaminoglycan (sGAG) loss in TNF-α-stimulated cartilage explants. Methods Explants from bovine stifle joints were stimulated with TNF-α for 1 day to induce cartilage degradation followed by supplementation with 50 mM potassium chloride (KCl), 50 mM lithium chloride (LiCl), 50 mM sodium chloride (NaCl), or 100 nM dexamethasone for an additional 6 days. We assessed the effect of TNF-α stimulation and hyperosmolar ionic treatment on sGAG loss and expression of OA-associated proteins: ADAMTS-5, COX-2, MMP-1, MMP-13, and VEGF. Results TNF-α treatment increased sGAG loss ( P < 0.001) and expression of COX-2 ( P = 0.018), MMP-13 ( P < 0.001), and VEGF ( P = 0.017) relative to unstimulated controls. Relative to activated controls, LiCl and dexamethasone treatment attenuated sGAG loss ( P = 0.008 and P = 0.042, respectively) and expression of MMP-13 ( P = 0.005 and P = 0.036, respectively). In contrast, KCl treatment exacerbated sGAG loss ( P = 0.032) and MMP-1 protein expression ( P = 0.010). NaCl treatment, however, did not alter sGAG loss or expression of OA-related proteins. Comparing LiCl and KCl treatment shows a potent reduction ( P < 0.05) in catabolic and inflammatory mediators following LiCl treatment. Conclusion These results suggest that these ionic species elicit varying responses in TNF-α-stimulated explants. Cumulatively, these findings support additional studies of hyperosmolar ionic solutions for potential development of novel intraarticular injections targeting OA.

Engineering osteoinductive, self‐fitting scaffolds offers a potential treatment modality to repair irregularly shaped craniomaxillofacial bone defects. Recently, we innovated on osteoinductive poly(ε‐caprolactone)‐diacrylate (PCL‐DA) shape memory polymers (SMPs) to incorporate poly‐L‐lactic acid (PLLA) into the PCL‐DA network, forming a semi‐interpenetrating network (semi‐IPN). Scaffolds formed from these PCL‐DA/PLLA semi‐IPNs display stiffnesses within the range of trabecular bone and accelerated degradation relative to scaffolds formed from slowly degrading PCL‐DA SMPs. Herein, we demonstrate for the first time that PCL‐DA/PLLA semi‐IPN SMP scaffolds show increased intrinsic osteoinductivity relative to PCL‐DA. We also confirm that application of a bioinspired polydopamine (PD) coating further improves the osteoinductive capacity of these PCL‐DA/PLLA semi‐IPN SMPs. In the absence of osteogenic supplements, protein level assessment of human mesenchymal stem cells (h‐MSCs) cultured in PCL‐DA/PLLA scaffolds revealed an increase in expression of osteogenic markers osterix, bone morphogenetic protein‐4 (BMP‐4), and collagen 1 alpha 1 (COL1A1), relative to PCL‐DA scaffolds and osteogenic medium controls. Likewise, the expression of runt‐related transcription factor 2 (RUNX2) and BMP‐4 was elevated in the presence of PD‐coating. In contrast, the chondrogenic and adipogenic responses associated with the scaffolds matched or were reduced relative to osteogenic medium controls, indicating that the scaffolds display intrinsic osteoinductivity.

Sophorolipids are a class of glycolipids that can be polymerized via ring-opening metathesis polymerization giving rise to bioresorbable biomaterials. The surface chemistry of the resulting poly­(sophorolipids) (pLSLs) can be modified using a combination of enzymatic and “click” chemistries to insert bioactive groups that influence cellular behavior. Mesenchymal stem cells (MSCs) are being actively investigated for engineered bone grafts for fracture repair due to their osteogenic potential, and more recently, due to their immunomodulatory capacity. The long-term goal of this work is to utilize functionalized pLSL foams loaded with MSCs as bioresorbable scaffolds for bone fracture healing. Toward this goal, the present study evaluated the effect of various pLSL chemistries on the osteogenic and immunomodulatory behavior of MSCs. pLSLs functionalized with PO4, NH2, or COOH small functional groups were fabricated into open porous foams and then cultured with MSCs in the presence of osteogenic medium for 72 h. Protein level assessments demonstrated that the PO4-functionalized pLSL foams supported the highest degree of MSC osteogenesis as well as the highest levels of immunomodulatory factors pertinent to improve bone fracture healing. Cumulatively, these results suggest that further investigation of the long-term osteogenic commitment of MSCs in PO4-functionalized pLSL foams is warranted.