Preparation and Characterization of Polylactic Acid/Nano Hydroxyapatite/Nano Hydroxyapatite/Human Acellular Amniotic Membrane (PLA/nHAp/HAAM) Hybrid Scaffold for Bone Tissue Defect Repair

Acceleration of bone healing by a growth factor-releasing allo-hybrid graft

INTRODUCTION

Human amniotic membrane (hAM) has a highly biocompatible natural scaffold that is abundant in several extracellular matrix (ECM) components, including but not limited to platelet-derived growth factor (PDGF), transforming growth factor (TGF), and fibroblast growth factor (FGF). In our study, we have focused on a mixture of hAM and demineralized bone matrix (DBM) as an allo-hybrid graft to deliver it into the site of bone defect to decrease bone remodeling time.

METHODS

Allo-hybrid grafts were prepared by coating the jelly made of decellularized and lyophilized hAM (AMJ) on the surface of DBM and subsequently underwent in vitro studies, such as alkaline phosphatase activity, MTT assay, and SEM analysis. Twenty-four male rats were included in the study, and after creating calvarial defects, rats were divided into four groups: DBM implanted, allo-hybrid implanted, AMJ injection, and a negative control (NC). Bone regeneration was assessed using computed tomography (CT scan) and histological analysis at 1, 2, and 3 months after surgery.

RESULTS

CT scan analysis clearly showed improved new bone growth in the allo-hybrid group compared to the NC group. Also, the Hounsfield unit of the allo-hybrid group (774.91 ± 47.8) after 90 days confirms CT scans. Histological staining revealed immature bone in allo-hybrid and DBM groups, along with the creation of a medullary cavity and bone marrow two months after surgery. Three months after surgery, the allo-hybrid group showed signs of new, mature bone, while no sign of healing could be seen in the NC group at any time points. Over a 90-day period, the allo-hybrid group recovered the bone defect area near 90 %. It is relatively twice as much as AMJ group.

CONCLUSION

Histological properties of bone defects and bone regeneration can both be improved by allo-hybrid grafts coated with AMJ.

Efficacy of Bone Morphogenetic Protein-2 Peptide-Modified Nano-Hydroxyapatite Alginate Hydrogel in Vertebral Bone Defect Repair

For the effective treatment of vertebral bone defects (BDs), the authors constructed an innovative hydroxyapatite (HAP) nanoparticle-hyaluronic acid (HA)-alginate (ALG) scaffold loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2). The particle size of HAP was around 80 to 100 nm, and its addition markedly reduced the swelling rate and degradability of the HA-ALG scaffold while enhancing its compression resistance, enabling it to better support the BD site and provide a good proliferation environment for osteoblasts. Furthermore, HAP-HA-ALG effectively extended the half-life of rhBMP-2 by nearly 50-fold, allowing it to exert its osteogenic effects more consistently. In cellular experiments, the authors found that rhBMP-2@HAP-HA-ALG significantly enhanced the activity and migration ability of bone marrow mesenchymal stromal cells, as well as the expression level of related osteogenic proteins in cells, which better exerted osteoinductive and osteoconductive functions. In animal tests, rhBMP-2@HAP-HA-ALG could better facilitate the generation of new bone and bone trabecula at BD sites and markedly enhance the bone density level, thus shortening the repair time of BDs. Therefore, rhBMP-2@HAP-HA-ALG shows great potential in the restoration of vertebral BDs.

Adenoid cystic carcinoma of the tongue: A case study highlighting surgical management of an exceptionally rare entity

BACKGROUND

Adenoid cystic carcinoma (ACC) is a rare malignant tumor that accounts for <1 % of head and neck malignancies, with an estimated involvement of the tongue at approximately 3 %.

CASE PRESENTATION

This report presents a case of a 42-year-old male with no significant history of tobacco or alcohol use, who developed a painless, progressively enlarging mass on the ventral surface of his tongue over the course of eight months. Initial surgical resection confirmed the diagnosis of ACC, which necessitated a right hemiglossectomy followed by radiotherapy to address potential residual disease.

DISCUSSION

ACC of the tongue presents unique clinical challenges due to its rarity and aggressive nature. The lack of traditional risk factors indicates that ACC can arise in low-risk populations, underscoring the necessity for heightened awareness among healthcare professionals to facilitate early detection. Surgical resection remains the standard treatment; however, achieving negative margins is challenging due to the tumor's infiltrative characteristics, which can lead to local recurrence. Histologically, ACC is classified as a biphasic neoplasm often associated with perineural invasion, and high-grade transformation increases the risk of metastasis. Postoperative radiotherapy is recommended to reduce the risk of recurrence, particularly in cases exhibiting unfavorable histological features. A personalized treatment strategy that takes into account tumor characteristics and patient-specific factors is essential for effective management.

CONCLUSION

This case underscores the importance of vigilance in identifying symptoms of ACC of the tongue, even in low-risk individuals. It advocates for a multidisciplinary approach that includes surgical intervention and adjuvant radiotherapy to achieve optimal outcomes.

Hybrid thermosensitive hydrogel/amniotic membrane structure incorporating S-nitrosothiol microparticles: potential uses for controlled nitric oxide delivery

Insufficient levels of nitric oxide may lead to chronic and acute wounds. Additionally, it is crucial that nitric oxide is prepared in a controlled-release manner due to its gaseous nature and short half-life. To address this issue, utilizing nitric oxide donors, particularly S-nitrosothiols such as S-nitrosoglutathione (GSNO), could efficiently overcome instability and aid in biomedical applications. Decellularized human amniotic membranes are also best known for their anti-inflammatory, angiogenic, and antimicrobial properties to promote wound epithelization. In this study, a novel nitric oxide-generated wound dressing based on an amniotic membrane was investigated. This construct consisted of a chitosan/β-glycerophosphate thermosensitive hydrogel covered with a decellularized human amniotic layer embedded with GSNO-loaded polylactic acid microparticles. The structure of GSNO was confirmed by spectrometric, elemental, and chemical analyses. The GSNO-loaded microparticles had a diameter of 40.66 ± 6.92 µm, and an encapsulation efficiency of 45.6 ± 6.74%. The hybrid construct and GSNO-loaded microparticles enhanced the long-term stable release of GSNO compared to free GSNO. The construct released nitric oxide ranging from 24 to 68 nM/mg during 7 days. The thermosensitive hydrogel was formed at 32.7 ± 1 °C and had a porous structure with a pore size of 41.76 ± 9.76 µm. The MTT and live/dead assays performed on human dermal fibroblast cells demonstrated suitable cell viability and adhesion to the final construct. Further, hemolysis analysis revealed less than a 5% hemolysis rate due to negligible blood cell adhesion. Overall, the prepared hybrid construct demonstrated suitable characteristics as a potential active wound dressing capable of controlled nitric oxide delivery.

Osteochondral Tissue Engineering: Scaffold Materials, Fabrication Techniques and Applications

Osteochondral damage, caused by trauma, tumors, or degenerative diseases, presents a major challenge due to the limited self-repair capacity of the tissue. Traditional treatments often result in significant trauma and unpredictable outcomes. Recent advances in bone/cartilage tissue engineering, particularly in scaffold materials and fabrication technologies, offer promising solutions for osteochondral regeneration. This review highlights the selection and design of scaffolds using natural and synthetic materials such as collagen, chitosan (Cs), and polylactic acid (PLA), alongside inorganic components like bioactive glass and nano-hydroxyapatite (nHAp). Key fabrication techniques-freeze-drying, electrospinning, and 3D printing-have improved scaffold porosity and mechanical properties. Special focus is placed on the design of multiphasic scaffolds that mimic natural tissue structures, promoting cell adhesion and differentiation and supporting the regeneration of cartilage and subchondral bone. In addition, the current obstacles and future directions for regenerating damaged osteochondral tissues will be discussed.

The Combination of Super-Active Platelet Lysate and Acellular Amniotic Membrane Enhances Endometrial Receptivity, While Simultaneously Facilitating Endometrial Repair in Rats

Purpose

To investigate the combined effects of super-active platelet lysate (sPL) and acellular amniotic membrane (AAM) in promoting endometrial repair and enhancing endometrial receptivity in rats.

Methods

The characteristics of sPL-AAM were examined through scanning electron microscopy, contact angle tester, and release experiments. We aimed to establish a rat model for endometrial injury. We divided sixty-four rats into four groups: the Injury group (Control group), the AAM group, the sPL group, and the sPL-AAM group. Our study compared the endometrial thickness, gland count, and fibrotic area recovery in rats at 6 days and 18 days post-treatment. Immunohistochemistry was utilized to assess the expressions of CD34 and ANG. Additionally, we used ELISA to detect the levels of IL-6 and TNF-α, while Western Blot was employed to compare the expressions of CK19, Integrin β3, and TGF-β1. One month after the treatment, we evaluated and compared the pregnancy recovery among the groups.

Results

Compared to the Injury group, the sPL-AAM group demonstrated enhanced endometrial regeneration in rats at both 6 days and 18 days post-treatment, resulting in a favorable pregnancy outcome. This was achieved by promoting angiogenesis, suppressing the inflammatory response, and reducing fibrosis. The observed effects were superior to those of the sPL group alone. While sPL, when administered alone, showed some degree of endometrial restoration at 6 days post-treatment, its efficacy was diminished at 18 days post-treatment. The impact of AAM alone appeared inconspicuous compared to the injury group. This suggests that sPL serves as the primary agent in facilitating endometrial repair, while AAM functions as a carrier to extend the duration of sPL's effectiveness.

Conclusion

sPL-AAM can release effective cytokines, repair endometrial damage in rats, enhance endometrial receptivity, and ultimately improve pregnancy outcomes.

Amniotic Fluid Proteomics Analysis and In Vitro Validation to Identify Potential Biomarkers of Preterm Birth

This study aimed to investigate the regulation of amniotic fibroblast (AFC) function by vitamin K-dependent protein Z (PROZ) during preterm birth (PTB) and its potential role in adverse pregnancy outcomes. Proteomic samples were collected from amniotic fluid in the second trimester, and AFC were isolated from the amniotic membrane and cultured in vitro. The expression of extracellular and intracellular PROZ in AFC was modulated, and their biological properties and functions were evaluated. Clinical analysis revealed a significant upregulation of PROZ expression in amniotic fluid from preterm pregnant women. In vitro experiments demonstrated that PROZ stimulated AFC migration, enhanced their proliferative capacity, and reduced collagen secretion. Overexpression of PROZ further enhanced cell migration and proliferation, while knockdown of PROZ had the opposite effect. PROZ plays a crucial role in promoting the proliferation and migration of amniotic membrane fibroblasts. Increased PROZ expression in amniotic fluid is associated with the occurrence of PTB. These findings shed light on the potential involvement of PROZ in adverse pregnancy outcomes and provide a basis for further research on its regulatory mechanisms during PTB.

Mineralization, degradation and osteogenic property of polylactide multicomponent porous composites for bone repair: In vitro and in vivo study

Gelatin and hydroxyapatite were assembled into polylactide porous matrix to prepare multicomponent porous composites for bone repair (PLA-gH). PLA-gH possessed a superior ability of mineralization. During simulated body fluids (SBF), the spherical Ca-P depositions on surface of PLA-gH became bulk as Ca/P decreased, while they locally turned into the rod with different variation in Ca/P during SBF containing bovine serum albumin (SBF-BSA), indicating that the mineralization of PLA-gH could be regulated by BSA. Meanwhile, PLA-gH possessed good degradation behaviour, especially in SBF-BSA, the degradation of PLA porous matrix was higher than that in SBF after 14-day immersion, whose crystallinity (Xc) decreased to a slightly lower level. Gelatin and hydroxyapatite endowed PLA-gH with good osteogenic property, characterized by obvious osteogenic differentiation and bone regeneration. In terms of predicting the cytocompatibility, osteogenic differentiation and new bone mineralization of PLA-gH by in vitro methods, applying SBF-BSA may be more reliable than SBF.

Introduction to Amniotic Membranes in Maxillofacial Surgery-A Scoping Review

Background: Amniotic membrane (AM) holds significant promise in various medical fields due to its unique properties and minimal ethical concerns. This study aims to explore the diverse applications of the human amniotic membrane (HAM) in maxillofacial surgery. Methodology: A comprehensive search was conducted on databases, namely Google Scholar, PubMed, and Scopus, from January 1985 to March 2024. Articles in English, Polish, and Spanish were included, focusing on keywords related to amniotic membrane and oral surgery. Results: Various preservation methods for HAM were identified, namely fresh, decellularized, cryopreserved, lyophilized, and air-dried formats. Clinical studies demonstrated the efficacy of HAM in repairing oral mucosal defects, vestibuloplasty, oronasal fistula closure, cleft palate treatment, bone defect repair, and medication-related osteonecrosis of the jaw (MRONJ). Surgeon evaluations highlighted the ease of handling but noted challenges in suturing and stability during application. Conclusions: Amniotic membranes offer a versatile and effective option in maxillofacial surgery, promoting wound healing, reducing inflammation, and providing a scaffold for tissue regeneration. Further research, including randomized trials and comparative studies, is warranted to validate the efficacy and optimize the utilization of HAM in clinical practice.

Research advances of nanomaterials for the acceleration of fracture healing

The bone fracture cases have been increasing yearly, accompanied by the increased number of patients experiencing non-union or delayed union after their bone fracture. Although clinical materials facilitate fracture healing (e.g., metallic and composite materials), they cannot fulfill the requirements due to the slow degradation rate, limited osteogenic activity, inadequate osseointegration ability, and suboptimal mechanical properties. Since early 2000, nanomaterials successfully mimic the nanoscale features of bones and offer unique properties, receiving extensive attention. This paper reviews the achievements of nanomaterials in treating bone fracture (e.g., the intrinsic properties of nanomaterials, nanomaterials for bone defect filling, and nanoscale drug delivery systems in treating fracture delayed union). Furthermore, we discuss the perspectives on the challenges and future directions of developing nanomaterials to accelerate fracture healing.

Novel Nanoprobe with Combined Ultrasonography/Chemical Exchange Saturation Transfer Magnetic Resonance Imaging for Precise Diagnosis of Tumors

Given that cancer mortality is usually due to a late diagnosis, early detection is crucial to improve the patient's results and prevent cancer-related death. Imaging technology based on novel nanomaterials has attracted much attention for early-stage cancer diagnosis. In this study, a new block copolymer, poly(ethylene glycol)-poly(l-lactide) diblock copolymer (PEG-PLLA), was synthesized by the ring-opening polymerization method and thoroughly characterized using Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (H-NMR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The obtained PEG-PLLA was used to prepare nanoparticles encapsulated with perfluoropentane and salicylic acid by the emulsion-solvent evaporation method, resulting in a new dual-mode nano-image probe (PEG-PLLA@SA·PFP). The zeta potential and mean diameter of the obtained nanoparticles were measured using dynamic light scattering (DLS) with a Malvern Zetersizer Nano. The in vitro biocompatibility of the PEG-PLLA nanoparticles was evaluated with cell migration, hemolysis, and cytotoxicity assays. Ultrasonic imaging was performed using an ultrasonic imaging apparatus, and chemical exchange saturation transfer (CEST) MRI was conducted on a 7.0 T animal scanner. The results of IR and NMR confirmed that the PEG-PLLA was successfully synthesized. The particle size and negative charge of the nanoparticles were 223.8 ± 2.5 nm and -39.6 ± 1.9 mV, respectively. The polydispersity of the diameter was 0.153 ± 0.020. These nanoparticles possessed good stability at 4 °C for about one month. The results of cytotoxicity, cell migration, and hemolysis assays showed that the carrier material was biocompatible. Finally, PEG-PLLA nanoparticles were able to significantly enhance the imaging effect of tumors by the irradiation of ultrasound and saturation by a radiofrequency pulse, respectively. In conclusion, these nanoparticles exhibit promising dual-mode capabilities for US/CEST MR imaging.