Regenerating articular cartilage within osteoarthritis (OA)-affected joints remains a long-standing challenge. This study introduces a novel chemically modified silk-based biomaterial to modulate key signaling pathways involved in OA and cartilage repair. The designed biomaterial concurrently inhibits the bone morphogenetic protein (BMP) signaling, aberrantly activated during OA, and inherently facilitates Wnt/β-catenin signaling, a crucial factor for chondrogenesis and cartilage homeostasis. The dual modulation was achieved by covalently conjugating the potent BMP inhibitor LDN-193189 to the Silk Fibroin-Gelatin (SF-G) bioink. The chemically decorated SF-G construct served as a biomimetic delivery platform and a mechanically robust support, ideally suited for regenerating load-bearing articular cartilage. The functionalized material was implanted into a critical-sized cartilage defect in the rat femoral trochlear groove, which had been previously subjected to OA by anterior cruciate ligament transection. The results confirmed successful neocartilage regeneration, evidenced by dense Safranin O staining and expression of cartilage-specific collagen. The absence of hypertrophic markers, fibrocartilage, and inflammation indicates the authenticity of hyaline cartilage formation in a severe OA microenvironment. Overall, the LDN-193189-conjugated SF-G construct overcame the challenges of maintaining phenotypic stability in articular cartilage of OA joints, representing a promising regenerative approach for restoring lost cartilage.

The limited regeneration capacity of articular cartilage (AC) is attributed to the hypocellular nature of the cartilage tissue and the absence of vascularization. On the other hand, degenerative joint disease, such as osteoarthritis (OA), is characterized by irreversible AC degeneration and synovial inflammation, leading to pain, discomfort, and restricted joint mobility. The existing treatment options for OA mostly provide symptomatic relief. Therefore, it is vital to explore several approaches, such as cartilage regeneration and maintenance of cartilage homeostasis. During OA pathogenesis, significant changes are observed in the gene expression and phenotype of articular chondrocytes. Some of these changes include chondrocyte hypertrophy, expansion of the endoplasmic reticulum-Golgi apparatus, secretion of stiffer collagen matrix like collagen type X, increased matrix metalloproteinases (MMPs)-3, −9, and −13 and alkaline phosphatase levels; and decrease of SOX9, proteoglycans, and collagen type II. The changes seen in chondrocytes are similar to those observed during endochondral ossification. Therefore, modulating key molecular players like bone morphogenetic protein (BMP) and wingless-related integration site (Wnt) Wnt/β-catenin signaling pathways using their antagonists and agonists, respectively, has been shown to effectively inhibit OA progression. These advancements have been further explored in the context of cartilage tissue engineering to design artificial AC-like scaffolds that mimic former physicochemical properties and can be applied as a substitute for damaged cartilage. However, modern science still has unaccomplished objectives that can completely translate our understanding of AC maintenance into the complete restoration of healthy joints. Therefore, in this review, we looked at how understanding the cellular and molecular behavior of articular chondrocytes may be used in confluence with other existing non-surgical therapeutic approaches, such as nanomedicines, regenerative biology, and tissue engineering combined, to find a cure for OA.

Background: Mucormycosis cases are managed by extensive debridement of the affected tissues, with correction of predisposing risk factors and antifungal drugs. Amphotericin B is the drug of choice; however, few azoles also have a good activity against Mucorales. Therefore, the present study was done to determine the minimum inhibitory concentration (MIC) of antifungal drugs against Mucorales, causing COVID-19 associated mucormycosis in North India. Methods: After obtaining written and informed consent, we processed the received tissue, sputum, and gastric lavage samples as per standard mycological procedures. Subsequently, we determined itraconazole, posaconazole, isavuconazole and amphotericin B MIC against the isolated Mucorales (one from each patient) by broth microdilution using CLSIM38A3 guidelines. Results: We received 615 samples from the enrolled 269 patients with CAM. We observed broad aseptate hyphae in 329 fresh tissues, ten sputum and one gastric lavage sample, whereas 163 follow-up excised tissue had broad aseptate hyphae. In addition, 209 Mucorales were isolated with a predominance of Rhizopus arrhizus (n=183), followed by Rhizopus microsporus (n=21) and Rhizopus homothallicus (n=5). We determined MIC against 77 and 8 strains of R. arrhizus and R. microsporus, respectively. Posaconazole had the least MIC. 0.25, 1, 0.5, and 2µg/ml were the MIC50 of posaconazole, amphotericin B, isavuconazole and itraconazole against R. arrhizus strains, respectively, whereas it was 0.125, 0.1875, 0.5 and 2 µg/ml against R. microsporus, respectively. Conclusions: Lower posaconazole MIC makes it a preferred drug for managing the mucormycosis cases; however, availability and cost are the limitations. Thus, amphotericin B and itraconazole may be used in such conditions.

Purpose (the aim of the study): To analyze whether mechanical restoration of the joint microenvironment can recover the osteoarthritis-like cartilage to healthy cartilage in an immobilization-induced mice model.

NanomedicineVol. 19, No. 10 EditorialFuturistic senolytic drug incorporated nanomedicine therapy to treat osteoarthritisLaxmi Akhileshwar Jha‡, Bhupendra Kumar‡, Saurav Kumar Jha & Keshav Raj PaudelLaxmi Akhileshwar Jha‡ https://orcid.org/0009-0004-9223-2702Naraina Vidya Peeth Group of Institutions, Faculty of Pharmacy, Dr. A. P. J. Abdul Kalam Technical University, Kanpur, 0208020, Uttar Pradesh, India, Bhupendra Kumar‡ https://orcid.org/0009-0006-4361-1372Department of Biological Sciences & Bioengineering (BSBE), Indian Institute of Technology, Kanpur, 208016, Uttar Pradesh, India, Saurav Kumar Jha *Author for correspondence: E-mail Address: sauravj@iitk.ac.inhttps://orcid.org/0000-0002-9207-2997Department of Biological Sciences & Bioengineering (BSBE), Indian Institute of Technology, Kanpur, 208016, Uttar Pradesh, India & Keshav Raj Paudel **Author for correspondence: E-mail Address: Keshavraj.paudel@uts.edu.auhttps://orcid.org/0000-0002-3591-2080Centre for Inflammation, Centenary Institute & University of Technology Sydney, Faculty of Science, School of Life Sciences, Sydney, NSW, 2007, AustraliaPublished Online:1 Mar 2024https://doi.org/10.2217/nnm-2023-0348AboutSectionsView ArticleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinkedInRedditEmail View articleKeywords: drug deliverynanomedicineosteoarthritissenescencesenolyticsReferences1. Di Micco R, Krizhanovsky V, Baker D, D'adda Di Fagagna F. Cellular senescence in ageing: from mechanisms to therapeutic opportunities. Nat. Rev. Mol. Cell Biol. 22(2), 75–95 (2021).MedlineGoogle Scholar2. Campisi J. Aging, cellular senescence, and cancer. Annu. Rev. Physiol. 75, 685–705 (2013).Medline CASGoogle Scholar3. Onishi K, Utturkar A, Chang E, Panush R, Hata J, Perret-Karimi D. Osteoarthritis: a critical review. Crit. Rev. Phys Rehabil. Med. 24(3–4), 251–264 (2012).MedlineGoogle Scholar4. Astrike-Davis EM, Coryell P, Loeser RF. Targeting cellular senescence as a novel treatment for osteoarthritis. Curr. Opin. Pharmacol. 64, 102213 (2022).Medline CASGoogle Scholar5. Mcculloch K, Litherland GJ, Rai TS. Cellular senescence in osteoarthritis pathology. Aging Cell 16(2), 210–218 (2017).Medline CASGoogle Scholar6. Acosta JC, Banito A, Wuestefeld T et al. A complex secretory program orchestrated by the inflammasome controls paracrine senescence. Nat. Cell Biol. 15(8), 978–990 (2013).Medline CASGoogle Scholar7. Pfander D, Körtje D, Zimmermann R et al. Vascular endothelial growth factor in articular cartilage of healthy and osteoarthritic human knee joints. Ann. Rheum. Dis. 60(11), 1070–1073 (2001).Medline CASGoogle Scholar8. Hashimoto S, Creighton-Achermann L, Takahashi K, Amiel D, Coutts RD, Lotz M. Development and regulation of osteophyte formation during experimental osteoarthritis. Osteoarthr. Cartil. 10(3), 180–187 (2002).Medline CASGoogle Scholar9. Philipot D, Guerit D, Platano D et al. p16INK4a and its regulator miR-24 link senescence and chondrocyte terminal differentiation-associated matrix remodeling in osteoarthritis. Arthritis Res. Ther. 16(1), R58 (2014).MedlineGoogle Scholar10. Neuhold LA, Killar L, Zhao W et al. Postnatal expression in hyaline cartilage of constitutively active human collagenase-3 (MMP-13) induces osteoarthritis in mice. J. Clin. Invest. 107(1), 35–44 (2001).Medline CASGoogle Scholar11. Farr JN, Fraser DG, Wang H et al. Identification of senescent cells in the bone microenvironment. J. Bone Miner. Res. 31(11), 1920–1929 (2016).Medline CASGoogle Scholar12. Jeon OH, David N, Campisi J, Elisseeff JH. Senescent cells and osteoarthritis: a painful connection. J. Clin. Invest. 128(4), 1229–1237 (2018).MedlineGoogle Scholar13. Shane Anderson A, Loeser RF. Why is osteoarthritis an age-related disease? Best Pract. Res. Clin. Rheumatol. 24(1), 15–26 (2010).MedlineGoogle Scholar14. Kirkland JL, Tchkonia T. Senolytic drugs: from discovery to translation. J. Int. Med. 288(5), 518–536 (2020).Medline CASGoogle Scholar15. Jha SK, Imran M, Paudel KR, Mohammed Y, Hansbro P, Dua K. Treating primary lymphoma of the brain in AIDS patients via multifunctional oral nanoparticulate systems. Nanomedicine 17(7), 425–429 (2022).CASGoogle Scholar16. Maharjan R, Pangeni R, Jha SK et al. Anti-angiogenic effect of orally available pemetrexed for metronomic chemotherapy. Pharmaceutics 11(7), 1–22 (2019).Google Scholar17. Xiao L, Cui J, Sun Z, Liu Y, Zheng J, Dong Y. Therapeutic potential of nanotechnology-based approaches in osteoarthritis. Front. Pharmacol. 13, 920824 (2022).Medline CASGoogle Scholar18. Munoz-Espin D, Rovira M, Galiana I et al. A versatile drug delivery system targeting senescent cells. EMBO Mol. Med. 10(9), 1–18 (2018).MedlineGoogle Scholar19. Xu T, Cai Y, Zhong X et al. β-Galactosidase instructed supramolecular hydrogelation for selective identification and removal of senescent cells. Chem. Commun. 55(50), 7175–7178 (2019).Medline CASGoogle Scholar20. Ge M, Hu L, Ao H, Zi M, Kong Q, He Y. Senolytic targets and new strategies for clearing senescent cells. Mech. Ag. Dev. 195, 111468 (2021).Medline CASGoogle Scholar21. Amor C, Feucht J, Leibold J et al. Senolytic CAR T cells reverse senescence-associated pathologies. Nature 583(7814), 127–132 (2020).Medline CASGoogle Scholar22. Rabiei M, Kashanian S, Samavati SS, Derakhshankhah H, Jamasb S, Mcinnes SJ. Nanotechnology application in drug delivery to osteoarthritis (OA), rheumatoid arthritis (RA), and osteoporosis (OSP). J. Drug Deliv. Sci. Technol. 61, 102011 (2021).CASGoogle Scholar23. Robbins PD, Jurk D, Khosla S et al. Senolytic drugs: reducing senescent cell viability to extend health span. Annu. Rev. Pharmacol. Toxicol. 61, 779–803 (2021).Medline CASGoogle Scholar24. Jha SK, Kumar B, Paudel KR, Bandyopadhyay A. The application of bioglass to treat osteoarthritis. EXCLI J. 22, 1232–1234 (2023).MedlineGoogle ScholarFiguresReferencesRelatedDetails Vol. 19, No. 10 STAY CONNECTED Metrics Downloaded 36 times History Received 2 December 2023 Accepted 15 February 2024 Published online 1 March 2024 Published in print April 2024 Information© 2024 Expert Publishing Medicine Ltd trading as Taylor & FrancisKeywordsdrug deliverynanomedicineosteoarthritissenescencesenolyticsFinancial disclosureThe authors have no financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.Competing interests disclosureThe authors have no competing interests or relevant affiliations with any organization or entity with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.Writing disclosureNo writing assistance was utilized in the production of this manuscript.PDF download

Purpose (the aim of the study): To investigate the role of canonical BMP (Bone Morphogenetic Protein) and Wnt signaling in age-induced osteoarthritis (OA) and derive strategy for therapeutic interventions to achieve disease-modifying therapy of OA.

A mechanistic framework for age-induced osteoarthritis (OA) has remained largely elusive, leading to challenges in designing effective therapies for this debilitating disorder. Meanwhile, the models that induce OA in young animals through surgical, pharmacological, or genetic alterations fail to mimic OA that stems with age. In this study, we examined the molecular, cellular, and radiological changes in the articular cartilage (AC) of the C57BL/6J wild-type mice from postnatal day 15 to 3 years of age. In juvenile mice, AC, while all the layers express the BMPR1A receptor, only a thin layer of cells in the deep zone of AC express BMP ligands, and chondrocyte hypertrophy ensues first in this layer. With age, the BMP ligand expression domain expands throughout the AC, leading to BMP signaling activation and resultant chondrocyte hypertrophy. Further, exposure to healthy AC with BMP ligands was sufficient to induce premature OA-like changes in the young adult mice, suggesting BMP signaling is the limiting factor behind age-induced OA. We found that activation of BMP signaling upregulates ICAT expression, a known inhibitor of the canonical Wnt pathway in the AC. Our results suggest that with aging, the spread of BMP signaling throughout the cartilage is a certainty and the underlying cause for age-induced OA. Further, in situ inhibition of BMP signaling appears to be a potent therapeutic strategy for age-induced OA ### Competing Interest Statement The authors have declared no competing interest.

OBJECTIVE:To explore the significance of BMP signaling in osteoarthritis (OA) etiology, and thereafter propose a disease-modifying therapy for OA.METHODS:To examine the role of the BMP signaling in pathogenesis of OA, an Anterior Cruciate Ligament Transection (ACLT) surgery was performed to incite OA in C57BL/6J mouse line at postnatal day 120 (P120). Thereafter, to investigate whether activation of BMP signaling is necessary and sufficient to induce OA, we have used conditional gain- and loss-of-function mouse lines in which BMP signaling can be activated or depleted, respectively, upon intraperitoneal injection of tamoxifen. Finally, we locally inhibited BMP signaling through intra-articular injection of LDN-193189 pre- and post-onset surgically induced OA. The majority of the investigation has been conducted using micro-CT, histological staining, and immuno histochemistry to assess the disease etiology.RESULTS:Upon induction of OA, depletion of SMURF1-an intra-cellular BMP signaling inhibitor in articular cartilage coincided with the activation of BMP signaling, as measured by pSMAD1/5/9 expression. In mouse articular cartilage, the BMP gain-of-function mutation is sufficient to induce OA even without surgery. Further, genetic, or pharmacological BMP signaling suppression also prevented pathogenesis of OA. Interestingly, inflammatory indicators were also significantly reduced upon LDN-193189 intra-articular injection which inhibited BMP signaling and slowed OA progression post onset.CONCLUSION:Our findings showed that BMP signaling is crucial to the etiology of OA and inhibiting BMP signaling locally can be a potent strategy for alleviating OA.

Articular cartilage shows limited self-healing ability owing to its low cellularity and avascularity. Untreated cartilage defects display an increased propensity to degenerate, leading to osteoarthritis (OA). During OA progression, articular chondrocytes are subjected to significant alterations in gene expression and phenotype, including a shift towards a hypertrophic-like state (with the expression of collagen type X, matrix metalloproteinases-13, and alkaline phosphatase) analogous to what eventuates during endochondral ossification. Present OA management strategies focus, however, exclusively on cartilage inflammation and degradation. A better understanding of the hypertrophic chondrocyte phenotype in OA might give new insights into its pathogenesis, suggesting potential disease-modifying therapeutic approaches. Recent developments in the field of cellular/molecular biology and tissue engineering proceeded in the direction of contrasting the onset of this hypertrophic phenotype, but knowledge gaps in the cause–effect of these processes are still present. In this review we will highlight the possible advantages and drawbacks of using this approach as a therapeutic strategy while focusing on the experimental models necessary for a better understanding of the phenomenon. Specifically, we will discuss in brief the cellular signaling pathways associated with the onset of a hypertrophic phenotype in chondrocytes during the progression of OA and will analyze in depth the advantages and disadvantages of various models that have been used to mimic it. Afterwards, we will present the strategies developed and proposed to impede chondrocyte hypertrophy and cartilage matrix mineralization/calcification. Finally, we will examine the future perspectives of OA therapeutic strategies.

Osteoarthritis (OA) is a prominent musculoskeletal disorder with no effective therapy. Moreover, molecular aetiology of OA and the development and maintenance of articular cartilage are poorly understood. During OA, articular cartilage undergoes cellular and molecular changes reminiscent of transient cartilage, the embryonic precursor of endochondral bone. Previous studies from our lab suggest that during embryonic development, a precise spatio-temporally regulated WNT-BMP signaling interplay dictates differentiation of a common progenitor pool to either articular or transient cartilage fate in adjacent domains. While Wnt signaling promotes articular cartilage fate, transient cartilage differentiation is critically BMP signaling dependent. Moreover, any ectopic activation of BMP signalling embryonically, leads to ectopic transient cartilage differentiation at the expense of articular cartilage. In this study, we show that BMP signaling is sufficient and necessary for pathogenesis of OA by ectopically activating BMP signaling and depleting BMP ligands in adult mice articular cartilage, respectively. Similarly, human osteoarthritic specimens show upregulation of BMP signaling in the articular cartilage. A recent study based on our work (1), suggests that pharmacological inhibition of BMP signaling allows maintenance of hMSC derived chondrocytes, implanted in mice, for longer time duration (2). Similarly, we observe in vivo local pharmacological inhibition of BMP signaling resulted in delayed onset and reduced severity of OA in a mouse model of OA as well as long term protection from OA like changes. Therefore, pharmacological inhibition of BMP signaling and consequent block of transient cartilage differentiation of joint cartilage cells can be a potential disease modifying therapy for OA. Significance statement This manuscript provides new insights into the mechanistic basis for the maintenance of articular cartilage in adults. Here we demonstrate the role of BMP signaling in the pathogenesis of osteoarthritis in mice and humans. To the best of our understanding, this is the first (3)study investigating the relationship between molecular histological changes observed in the articular cartilage during osteoarthritis and inflammation. Moreover, we demonstrate that local inhibition of BMP signaling can be a potential disease modifying therapy for osteoarthritis which is among the most prominent musculoskeletal disorders.