Autologous bone grafts are commonly used as the gold standard to repair and regenerate diseased bones. However, they are strongly associated with postoperative complications, especially at the donor site, and increased surgical costs. In an effort to overcome these limitations, tissue engineering (TE) has been proposed as an alternative to promote bone repair. The successful outcome of tissue engineering depends on the microstructure and composition of the materials used as scaffold. Decellularized bone matrix-based biomaterials have been applied as bioscaffolds in bone tissue engineering. These biomaterials play an important role in providing the mechanical and physical microenvironment needed by cells to proliferate and survive. Decellularized extracellular matrix (dECM) can be used as a powder, hydrogel and electrospun scaffolds. These bioscaffolds mimic the native microenvironment due to their structure similar to the original tissue. The aim of this review is to highlight the bone decellularization techniques. Herein we discuss: (1) bone structure; (2) properties of an ideal scaffold; (3) the potential of decellularized bone as bioscaffolds; (4) terminal sterilization of decellularized bone; (5) cell removing confirmation in decellularized tissues; and (6) post decellularization procedures. Finally, the improvement of bone formation by dECM and the immunogenicity aspect of using the decellularized bone matrix are presented, to illustrate how novel dECM-based materials can be used as bioscaffold in tissue engineering. A comprehensive understanding of tissue engineering may allow for better incorporation of therapeutic approaches in bone defects allowing for bone repair and regeneration.

Osteoarthritis (OA) is the most common progressive condition affecting joints. It mainly affects the knees and hips as predominant weight-bearing joints. Knee osteoarthritis (KOA) accounts for a large proportion of osteoarthritis and presents numerous symptoms that impair quality of life, such as stiffness, pain, dysfunction, and even deformity. For more than two decades, intra-articular (IA) treatment options for managing knee osteoarthritis have included analgesics, hyaluronic acid (HA), corticosteroids, and some unproven alternative therapies. Before effective disease-modifying treatments for knee osteoarthritis, treatments are primarily symptomatic, mainly including intra-articular corticosteroids and hyaluronic acid, so these agents represent the most frequently used class of drugs for managing knee osteoarthritis. But research suggests other factors, such as the placebo effect, have an essential role in the effectiveness of these drugs. Several novel intra-articular therapies are currently in the clinical trial processes, such as biological therapies, gene and cell therapies. Besides, it has been shown that the development of novel drug nanocarriers and delivery systems could improve the effectiveness of therapeutic agents in osteoarthritis. This review discusses the various treatment methods and delivery systems for knee osteoarthritis and the new agents that have been introduced or are in development.

This research aims to design and fabricate a novel hydrogel-based composite as a functional biomimetic and biocompatible scaffold for amended osteoblastic differentiation of adipose-derived mesenchymal stem cells (ADMSCs). The extracellular matrix (ECM) hydrogel is an ideal scaffold in tissue engineering in terms of its structure mimics natural tissue. In this study, the fresh bovine femur was demineralized and decellularized; next, ECM hydrogel was obtained by digesting these matrices. Then, TiO₂ and curcumin-loaded hydrogel (Hy/Ti/Cur) was fabricated besides TiO₂-loaded hydrogel (Hy/Ti) and curcumin-loaded hydrogel (Hy/Cur). Comparing the scanning electron microscopy (SEM) images of the pure network hydrogel and the rough morphology of Hy/Ti/Cur revealed that curcumin and titanium dioxide were successfully loaded into the hydrogel. In addition, FTIR spectroscopy and X-ray diffraction (XRD) validated these findings. The findings of the hydrogels’ swelling test indicated the favourable impact of curcumin and titanium dioxide in hydrogels, which enhances water absorption capacity. Our results showed that the hydrogels were cytocompatible, and the cell viability on the hydrogels was elevated compared to the control. The synergistic effect of TiO₂ and Cur co-embedded on ECM hydrogel (Hy/Ti/Cur) stimulates bone differentiation markers, such as Runt-related transcription factor 2 (RUNX-2) and osteocalcin (OCN) in ADMSCs cultured in normal and osteogenic medium. Moreover, Alkaline Phosphatase (ALP) activity and calcium deposition of ADMSCs cultured on engineered hydrogels were increased. These experiments showed that newly fabricated hydrogel has the potential to induce osteogenesis, which is recommended as an attractive scaffold in bone tissue engineering.

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome defined by severe hypophosphatemia, bone loss, fractures, and muscle weakness. Identifying of the tumor site is often difficult. The primary treatment for Tumor-induced osteomalacia (TIO) is currently surgical resection. Removing the primary tumor is the most definitive treatment for this disease. Here we describe the case of a 32-year-old man who exhibited sever muscle weakness and pain that had continued for three years. The patient has three sisters and one brother, all of whom are completely healthy and free of bone and muscle problems. Laboratory data indicate low serum phosphorus, normal serum and urine calcium level, besides raised alkaline phosphatase level. Due to elevated phosphorus levels in the urine and the lack of an alternative source for phosphorus excretion, along with the absence of short stature, bone deformities, and a negative family history that might suggest the potential for Tumor-induced osteomalacia (TIO), an octreotide scan was performed to the localized the tumor site. The scan, corroborated by CT and MRI scans, displayed absorption in the right maxillary sinus. Surgical excision of the lesion confirmed it to be a central giant cell granuloma. Following surgery and without receiving any other treatment, the patient's phosphorus levels and clinical condition improved compared to before the surgical treatment. Subsequently, the symptoms of muscle weakness and skeletal pain significantly diminished, and the patient regained the ability to move. Tumor enucleation was conducted, and the pathological examination of the maxillary sinus lesion unveiled a central Giant cell granuloma. The patient had clinical and laboratory improvement after surgery. This finding confirmed our diagnosis of a paraneoplastic hypophosphatemia associated with a giant cell granuloma.

Biologically, the monomeric form of prolactin is the most active. In measurement methods, all forms of prolactin are included in the assay; therefore, the presence of macroprolactin, causes a false increase in prolactin and misdiagnosis of hyperprolactinemia. It seems that if an alternative method can be used to check macroprolactin, it would be helpful. The study aims to investigate the urinary level of prolactin and its relationship with serum levels in cases of suspected macroprolactinemia and determine whether these tests can serve as a novel, non-invasive, accessible, and cost-effective tool for diagnosing macroprolactinemia. In this cross-sectional study, patients who visited the Tabriz Imam Reza hospital clinic (2020–2021) with elevated prolactin levels. Prolactin and creatinine were checked in the urine and blood samples. After treating the serum with polyethylene glycol to precipitate macroprolactin, serum prolactin was measured again. The patients were divided into two groups. The first group, consisting of 19 individuals, with a recovery rate of more than 60%, formed the hyperprolactinemia group. The second group, comprising 36 individuals with a recovery rate of less than 60%, formed the macroprolactinemia group. The participants in this study were 50 individuals, comprising 10 men and 40 women. The mean urinary prolactin levels in the hyperprolactinemia group are 43.27 ± 15.53, and in the macroprolactinemia group, they are 32.58 ± 16.27. This difference was statistically significant. The median ratio of urinary prolactin to urinary creatinine is 0.03 in the hyperprolactinemia group and 0.02 in the macroprolactinemia group (p<0.05). The median ratio of serum prolactin to urinary prolactin in the hyperprolactinemia group is 32.6, and in the macroprolactinemia group, it is 45.5 (p < 0.01). Findings showed that the difference between urinary prolactin in true macroprolactinemic and hyperprolactinemic patients is significant, such that the amount of urinary prolactin in macroprolactinemic patients is less than in hyperprolactinemic patients, and the ratio of serum to urinary prolactin is higher. These parameters can be used to detect macroprolactin in cases of increased serum prolactin level, and this finding could provide a basis for the idea that these parameters can be used as an alternative to the PEG sedimentation test for diagnosing macroprolactin.