Tissue engineering and regenerative medicine in musculoskeletal oncology

Cross-cultural adaptation and validation of a self-reporting tool to assess health-related quality of life for Egyptians with extremity bone sarcomas in childhood or adolescence

BACKGROUND

Validated self-reporting tools are required to evaluate the functional outcome and health-related quality of life (HRQOL) for those who had extremity bone sarcomas in their childhood or adolescence. Our study pursued cross-cultural adaptation and validation of the pediatric Toronto Extremity Salvage Score (pTESS) and Toronto Extremity Salvage Score (TESS) to assess the functional outcome for Egyptian children and adult survivors following surgeries of extremity bone sarcomas. In the modified versions of pTESS and TESS, mental domains were added to allow the evaluation of HRQOL using a specific instrument for childhood bone cancer.

METHODS

The internal consistency and test-retest reliability of the studied forms were assessed with Cronbach's alpha and Intra-class coefficients (ICC), respectively. For convergent validity, correlations between scores of the generic Pediatric Quality of Life Inventory (PedsQL 4.0) and pTESS /TESS scores were reported. Factor Analysis was feasible for pTESS-leg; due to the insufficient samples, only the average inter-item correlation coefficients were reported for the remaining versions.

RESULTS

Out of 233 participants, 134 responded to pTESS-leg, 53 to TESS-leg, 36 to pTESS-arm, and only 10 to TESS-arm. All versions showed excellent internal consistency (Cronbach's alpha >0.9), good test-retest reliability (ICC >0.8), moderate to strong correlations with PedsQL, and acceptable average inter-item correlation coefficients (≥0.3). Three factors were extracted for the pTESS-leg, in which all mental items were loaded on one separate factor with factor loadings exceeding 0.4. Active chemotherapy, less than one year from primary surgery, or tibial tumors were associated with significantly inferior pTESS/TESS scores in the lower extremity group.

CONCLUSION

The Egyptian pTESS and TESS are valid and reliable self-reporting tools for assessing the functional outcome following surgeries for extremity bone sarcomas. The modified pTESS and TESS versions, which include additional mental domains, enabled the assessment of the overall health status of our population. Future studies should include a larger sample size and evaluate the ability of pTESS/TESS to track progress over time.

Skull Base Regeneration During Treatment With Chemoradiation for Nasopharyngeal Carcinoma: A Case Report

BACKGROUND

Advanced cases of nasopharyngal carcinoma can present with skull base invasion. Treatment of these advanced cases with radiotherapy poses a challenge given proximity of tumor to critical neural structures as well as concern that a skull base defect and associated complications could develop with tumor regression.

CASE PRESENTATION

A 34-year-old male patient presented with a 7-cm nasopharyngeal tumor invading the skull base with destruction of the clivus and intracranial extension. He underwent a course of definitive chemoradiation, requiring use of adaptive radiotherapy, that resulted in complete tumor regression and is free of disease 5 years posttreatment. Imaging done during treatment demonstrated that significant regeneration of bone occurred simultaneously with tumor regression.

CONCLUSIONS

This case demonstrates that it is possible for bony regeneration to occur simultaneously with tumor regression in a patient with skull base invasion by tumor, precluding the need for neurosurgical intervention.

A Spheroid Model of Early and Late-Stage Osteosarcoma Mimicking the Divergent Relationship between Tumor Elimination and Bone Regeneration

Osteosarcoma is the most diagnosed bone tumor in children. The use of tissue engineering strategies after malignant tumor resection remains a subject of scientific controversy. As a result, there is limited research that focuses on bone regeneration postresection, which is further compromised following chemotherapy. This study aims to develop the first co-culture spheroid model for osteosarcoma, to understand the divergent relationship between tumor elimination and bone regeneration. By manipulating the ratio of stromal to osteosarcoma cells the modelled cancer state (early/late) is modified, as is evident by the increased tumor growth rates and an upregulation of a panel of well-established osteosarcoma prognostic genes. Validation of the authors' model is conducted by analyzing its ability to mimic the cytotoxic effects of the FDA-approved chemotherapeutic Doxorubicin. Next, the model is used to investigate what effect osteogenic supplements have, if any, on tumor growth. When their model is treated with osteogenic supplements, there is a stimulatory effect on the surrounding stromal cells. However, when treated with chemotherapeutics this stimulatory effect is significantly diminished. Together, the results of this study present a novel multicellular model of osteosarcoma and provide a unique platform for screening potential therapeutic options for osteosarcoma before conducting in vivo experiments.

Empty pelvis syndrome: a systematic review of reconstruction techniques and their associated complications

AIM

Empty pelvis syndrome is a major contributor to morbidity following pelvic exenteration. Several techniques for filling the pelvis have been proposed; however, there is no consensus on the best approach. We evaluated and compared the complications associated with each reconstruction technique with the aim of determining which is associated with the lowest incidence of complications related to the empty pelvis.

METHOD

The systematic review protocol was prospectively registered with PROSPERO (CRD42021239307). PRISMA-P guidelines were used to present the literature. PubMed and MEDLINE were systematically searched up to 1 February 2021. A dataset containing predetermined primary and secondary outcomes was extracted.

RESULTS

Eighteen studies fulfilled our criteria; these included 375 patients with mainly rectal and gynaecological cancer. Only three studies had a follow-up greater than 2 years. Six surgical interventions were identified. Mesh reconstruction and breast prosthesis were associated with low rates of small bowel obstruction (SBO), entero-cutaneous fistulas and perineal hernia. Findings for myocutaneous flaps were similar; however, they were associated with high rates of perineal wound complications. Omentoplasty was found to have a high perineal wound infection rate (40%). Obstetric balloons were found to have the highest rates of perineal wound dehiscence and SBO. Silicone expanders effectively kept small bowel out of the pelvis, although rates of pelvic collections remained high (20%).

CONCLUSION

The morbidity associated with an empty pelvis remains considerable. Given the low quality of the evidence with small patient numbers, strong conclusions in favour of a certain technique and comparison of these interventions remains challenging.

The optimized drug delivery systems of treating cancer bone metastatic osteolysis with nanomaterials

Some cancers such as human breast cancer, prostate cancer, and lung cancer easily metastasize to bone, leading to osteolysis and bone destruction accompanied by a complicated microenvironment. Systemic administration of bisphosphonates (BP) or denosumab is the routine therapy for osteolysis but with non-negligible side effects such as mandibular osteonecrosis and hypocalcemia. Thus, it is imperative to exploit optimized drug delivery systems, and some novel nanotechnology and nanomaterials have opened new horizons for scientists. Targeted and local drug delivery systems can optimize biodistribution depending on nanoparticles (NPs) or microspheres (MS) and implantable biomaterials with the controllable property. Drug delivery kinetics can be optimized by smart and sustained/local drug delivery systems for responsive delivery and sustained delivery. These delicately fabricated drug delivery systems with special matrix, structure, morphology, and modification can minimize unexpected toxicity caused by systemic delivery and achieve desired effects through integrating multiple drugs or multiple functions. This review summarized recent studies about optimized drug delivery systems for the treatment of cancer metastatic osteolysis, aimed at giving some inspiration in designing efficient multifunctional drug delivery systems.

Innovative Biomaterials for the Treatment of Bone Cancer

Bone cancer is a demanding challenge for contemporary medicine due to its high frequency of presentation and significant heterogeneity of malignant lesions developing within the bone. To date, available treatments are rarely curative and are primarily aimed at prolonging patients' survival and ameliorating their quality of life. Furthermore, both pharmacological and surgical therapies are aggravated by a consistent burden of adverse events and subsequent disability due to the loss of healthy bone structural and functional properties. Therefore, great research efforts are being made to develop innovative biomaterials able to selectively inhibit bone cancer progression while reducing the loss of bone structural properties secondary to local tissue invasion. In this review, we describe the state of the art of innovative biomaterials for the treatment of bone cancer. Along with physiological bone remodeling, the development of bone metastasis and osteosarcoma will be depicted. Subsequently, recent advances on nanocarrier-based drug delivery systems, as well as the application of novel, multifunctional biomaterials for the treatment of bone cancer will be discussed. Eventually, actual limitations and promising future perspectives regarding the employment of such approaches in the clinical scenario will be debated.

Osteosarcoma, personalized medicine, and tissue engineering; an overview of overlapping fields of research

INTRODUCTION

Osteosarcoma is a common bone malignancy in patients of all ages. Surgical and chemotherapy interventions fail to shrink tumor growth and metastasis. The development of efficient patient-specific therapeutic strategies for osteosarcoma is of great interest in tissue engineering and personalized medicine. The present manuscript aimed to review the advancements in tissue engineering and personalized medicine strategies to overcome osteosarcoma and the relevant biological aspects as well as the current tumor models in vitro and in vivo.

RESULTS

Tissue engineering and personalized medicine contribute to gene/cell engineering and cell-based therapies specific to genomic and proteomic profiles of individual patients to improve the current treatment options. Also, tissue engineering scaffolds provide physical support to missing bones, could trap cancer cells and deliver immune cells. Taken together, these strategies suppress tumor growth, angiogenic potential, and the subsequent metastasis as well as elicit desirable immune responses against tumor mass.

DISCUSSION

Advanced and high-throughput gene and protein identification technologies have facilitated the recognition of genomic and proteomic profiles of patients to design and develop patient-specific treatments. The pre-clinical studies showed promising outcomes to inhibit tumor growth and invasion but controversial results compared to clinical investigations make the importance of more clinical reports inevitable. The experimental tumor models assist the evolution of effective treatments by understanding the mechanisms of tumor progression.

CONCLUSION

Tissue engineering and personalized medicine strategies seem encouraging alternatives to conventional therapies against osteosarcoma. Modeling the tumor microenvironment coupled with pre-clinical results give new intelligence into the translation of strategies into the clinic.

Calcium phosphate cements: Optimization toward biodegradability

Synthetic calcium phosphate (CaP) ceramics represent the most widely used biomaterials for bone regenerative treatments due to their biological performance that is characterized by bioactivity and osteoconductive properties. From a clinical perspective, injectable CaP cements (CPCs) are highly appealing, as CPCs can be applied using minimally invasive surgery and can be molded to optimally fill irregular bone defects. Such CPCs are prepared from a powder and a liquid component, which upon mixing form a paste that can be injected into a bone defect and hardens in situ within an appropriate clinical time window. However, a major drawback of CPCs is their poor degradability. Ideally, CPCs should degrade at a suitable pace to allow for concomitant new bone to form. To overcome this shortcoming, control over CPC degradation has been explored using multiple approaches that introduce macroporosity within CPCs. This strategy enables faster degradation of CPC by increasing the surface area available to interact with the biological surroundings, leading to accelerated new bone formation. For a comprehensive overview of the path to degradable CPCs, this review presents the experimental procedures followed for their development with specific emphasis on (bio)material properties and biological performance in pre-clinical bone defect models.

Rabbit umbilical cord mesenchymal stem cells: A new option for tissue engineering

BACKGROUND

The source and availability of cells for tissue engineering in large scale research or clinical trials requires special attention. We propose the idea of applying rabbit umbilical cord mesenchymal stem cells for this purpose.

METHODS

Here, the structure of the rabbit umbilical cord was analyzed and compared to that of human umbilical cord, both macroscopically and histologically. Next, we isolated, cultured and identified the proliferative activity and immunological characteristics of rabbit umbilical cord mesenchymal stem cells in vitro using mixed lymphocyte reaction, flow cytometry and an enzyme-linked immunosorbent assay. Furthermore, we evaluated the effects of biphasic calcium phosphate ceramic scaffolds seeded with rabbit umbilical cord mesenchymal stem cells in rat cranial defect models using multiple techniques, including radiological, histological and immunohistochemistry.

RESULTS

In vitro studies demonstated a high level of proliferation and multi-lineage differentiation potential in rabbit umbilical cord mesenchymal stem cells. Rabbit umbilical cord mesenchymal stem cells exibited low immunogenicity properties and immune suppression capability with respect to both the allogeneic and xenogeneic immune response. The results of the in vivo study showed that rabbit umbilical cord mesenchymal stem cells could promote osteogenesis in heterogeneous hosts.

CONCLUSIONS

The rabbit umbilical cord mesenchymal stem cells may be a new source for tissue engineering.

Nanostructured Biomaterials for Bone Regeneration

This review article addresses the various aspects of nano-biomaterials used in or being pursued for the purpose of promoting bone regeneration. In the last decade, significant growth in the fields of polymer sciences, nanotechnology, and biotechnology has resulted in the development of new nano-biomaterials. These are extensively explored as drug delivery carriers and as implantable devices. At the interface of nanomaterials and biological systems, the organic and synthetic worlds have merged over the past two decades, forming a new scientific field incorporating nano-material design for biological applications. For this field to evolve, there is a need to understand the dynamic forces and molecular components that shape these interactions and influence function, while also considering safety. While there is still much to learn about the bio-physicochemical interactions at the interface, we are at a point where pockets of accumulated knowledge can provide a conceptual framework to guide further exploration and inform future product development. This review is intended as a resource for academics, scientists, and physicians working in the field of orthopedics and bone repair.

Evaluation of Preclinical Models for the Testing of Bone Tissue-Engineered Constructs

Autologous bone grafting is the clinical gold standard for the treatment of large bone defects, but it can only be obtained in limited amounts and is associated with donor site morbidity. These challenges might be overcome by tissue engineering (TE). Although promising results have been reported, translation into clinics often fails. Lack of reproducibility in preclinical studies may be one of the reasons. We evaluated preclinical models for testing of novel TE strategies, as well as the perception of researchers and clinicians toward the models. Therefore, a review of publications on preclinical models of the past 10 years was performed. A survey addressed to both clinicians and scientists was conducted to assess the clinical need for bone tissue engineering (BTE) constructs and researchers were asked about their satisfaction with the currently available preclinical models. A literature review revealed 169 articles on in vivo studies in the field of BTE, including 26 studies utilizing large animal models and 143 studies in small animals, with rabbits and rats presenting the most commonly used species. Only a few studies used skeletally mature animals, which is in large contrast to the patients targeted. The localization of the bone defects varied, but the vast majority (60%) were segmental bone defects with various fixation techniques. Results of 70 surveys confirmed a great clinical need for TE constructs and positive perceptions of all participants toward its future clinical application. Nevertheless, the need for optimization of preclinical models and limitations when it comes to translation of results to the clinical situation were indicated. No clear trends were detected with regards to the preclinical model, leading to most satisfying results despite the trend that scientists rated generally large animal models higher than small animal models. Results of the literature review and the survey reveal the lack of standardized methods. Despite the affirmed clinical need as well as a very positive perception of clinicians toward the use of TE, results indicate a critical need to optimize preclinical models and, in particular, improve translational aspects of the models. A consensus in the field on a limited number of well-standardized models should be reached.

Amorphous TiO2 Nanotubes as a Platform for Highly Selective Phosphopeptide Enrichment

This work reports highly selective phosphopeptide enrichment using amorphous TiO₂ nanotubes (TiO₂NTs) and the same material decorated with superparamagnetic Fe₃O₄ nanoparticles (TiO₂NTs@Fe₃O₄NPs). TiO₂NTs and TiO₂NTs@Fe₃O₄NPs materials were applied for phosphopeptide enrichment both from a simple peptide mixture (tryptic digest of bovine serum albumin and α-casein) and from a complex peptide mixture (tryptic digest of Jurkat T cell lysate). The obtained enrichment efficiency and selectivity for phosphopeptides of TiO₂NTs and TiO₂NTs@Fe₃O₄NPs were increased to 28.7 and 25.3%, respectively, as compared to those of the well-established TiO₂ microspheres. The enrichment protocol was extended for a second elution step facilitating the identification of additional phosphopeptides. It further turned out that both types of amorphous TiO₂ nanotubes provide qualitatively new physicochemical features that are clearly advantageous for highly selective phosphopeptide enrichment. This has been confirmed experimentally resulting in substantial reduction of non-phosphorylated peptides in the enriched samples. In addition, TiO₂NTs@Fe₃O₄NPs combine high selectivity and ease of handling due to the superparamagnetic character of the material. The presented materials and performances are further promising for applications toward a whole range of other types of biomolecules to be treated in a similar fashion.

Recent advances in musculoskeletal local drug delivery

Musculoskeletal disorders are a significant burden on the global economy and public health. Advanced drug delivery plays a key role in the musculoskeletal field and holds the promise of enhancing the repair of degenerated and injured musculoskeletal tissues. Ideally, drug delivery should have the ability to directly deliver therapeutic agents to the diseased/injured sites with a desirable drug level over a period of time. Here, we present a mini-review of the current state-of-the-art research associated with local drug delivery and its use for the treatment of musculoskeletal disorders. First, an overview of drug delivery strategies, with a focus on issues related to musculoskeletal pathology, potential therapeutic strategies, conventional and non-conventional drugs, and various delivery systems, is introduced. Then, we highlight recent advances in the emerging fields of musculoskeletal local drug delivery, involving therapeutic drugs (e.g., genes, small molecule therapeutics, and stem cells), novel delivery vehicles (e.g., 3D printing and tissue engineering techniques), and innovative delivery approaches (e.g., multi-drug delivery and smart stimuli-responsive delivery). The review concludes with future perspectives and associated challenges for developing local drug delivery for musculoskeletal applications. STATEMENT OF SIGNIFICANCE: Three important aspects are highlighted in this manuscript: 1) The advanced musculoskeletal drug delivery is introduced from the aspects ranging from musculoskeletal disorders, potential therapeutic solutions, and various drug delivery systems. 2) The recent advances in the emerging fields of musculoskeletal local drug delivery, involving therapeutic drugs (e.g., genes, small molecule therapeutics, and stem cells), novel delivery vehicles (e.g., 3D printing and tissue engineering technique), and innovative delivery approaches (e.g., multi-drug delivery and smart stimuli-responsive delivery), are highlighted. 3) The challenges and perspectives of future research directions in the development of musculoskeletal local drug delivery are presented.

miR-34a promotes bone regeneration in irradiated bone defects by enhancing osteoblastic differentiation of mesenchymal stromal cells in rats

Background

Radiation exposure negatively affects the regenerative ability and makes reconstruction of bone defects after tumor section difficult. miR-34a is involved in radiation biology and bone metabolism. The aim of this study was to investigate whether miR-34a could contribute to bone regeneration in irradiated bone defects.

Methods

The expression of miR-34a was analyzed during the osteoblastic differentiation of irradiated BMSCs and bone formation in irradiated bone defects. miR-34a mimics and miR-34a inhibitor were used to upregulate or suppress the expression of miR-34a in BMSCs irradiated with 2 or 4 Gy X-ray radiation. In vitro osteogenesis and subcutaneous osteogenesis were used to assess the effects of miR-34a on the osteogenic ability of radiation-impaired BMSCs. Collagen-based hydrogel containing agomiR-34a or antagomiR-34a were placed into the 3-mm defects of irradiated rat tibias to test the effect of miR-34a on bone defect healing after irradiation.

Results

miR-34a was upregulated in the process of bone formation after irradiation. Transfecting radiation-impaired BMSCs with miR-34a mimics enhanced their osteoblastic differentiation in vitro by targeting NOTCH1. Overexpression of miR-34a enhanced the ectopic bone formation of irradiated BMSCs. In situ delivery of miR-34a promoted bone regeneration in irradiated bone defects.

Conclusions

miR-34a promoted the osteoblastic differentiation of BMSCs and enhanced the ectopic bone formation after irradiation. miR-34a promoted bone defect healing in irradiated rat tibias. miR-34a-targeted therapy might be a promising strategy for promoting the reconstruction of bone defects after radiotherapy.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1285-y) contains supplementary material, which is available to authorized users.

Mesenchymal stromal cells for bone sarcoma treatment: Roadmap to clinical practice

Over the past few decades, there has been growing interest in understanding the molecular mechanisms of cancer pathogenesis and progression, as it is still associated with high morbidity and mortality. Current management of large bone sarcomas typically includes the complex therapeutic approach of limb salvage or sacrifice combined with pre- and postoperative multidrug chemotherapy and/or radiotherapy, and is still associated with high recurrence rates. The development of cellular strategies against specific characteristics of tumour cells appears to be promising, as they can target cancer cells selectively. Recently, Mesenchymal Stromal Cells (MSCs) have been the subject of significant research in orthopaedic clinical practice through their use in regenerative medicine. Further research has been directed at the use of MSCs for more personalized bone sarcoma treatments, taking advantage of their wide range of potential biological functions, which can be augmented by using tissue engineering approaches to promote healing of large defects. In this review, we explore the use of MSCs in bone sarcoma treatment, by analyzing MSCs and tumour cell interactions, transduction of MSCs to target sarcoma, and their clinical applications on humans concerning bone regeneration after bone sarcoma extraction.

[Scaffold-based Bone Tissue Engineering]

Tissue engineering provides the possibility of regenerating damaged or lost osseous structures without the need for permanent implants. Within this context, biodegradable and bioresorbable scaffolds can provide structural and biomechanical stability until the body's own tissue can take over their function. Additive biomanufacturing makes it possible to design the scaffold's architectural characteristics to specifically guide tissue formation and regeneration. Its nano-, micro-, and macro-architectural properties can be tailored to ensure vascularization, oxygenation, nutrient supply, waste exchange, and eventually ossification not only in its periphery but also in its center, which is not in direct contact with osteogenic elements of the surrounding healthy tissue. In this article we provide an overview about our conceptual design and process of the clinical translation of scaffold-based bone tissue engineering applications.

Emergence of synthetic mRNA: In vitro synthesis of mRNA and its applications in regenerative medicine

The field of gene therapy has evolved over the past two decades after the first introduction of nucleic acid drugs, such as plasmid DNA (pDNA). With the development of in vitro transcription (IVT) methods, synthetic mRNA has become an emerging class of gene therapy. IVT mRNA has several advantages over conventional pDNA for the expression of target proteins. mRNA does not require nuclear localization to mediate protein translation. The intracellular process for protein expression is much simpler and there is no potential risk of insertion mutagenesis. Having these advantages, the level of protein expression is far enhanced as comparable to that of viral expression systems. This makes IVT mRNA a powerful alternative gene expression system for various applications in regenerative medicine. In this review, we highlight the synthesis and preparation of IVT mRNA and its therapeutic applications. The article includes the design and preparation of IVT mRNA, chemical modification of IVT mRNA, and therapeutic applications of IVT mRNA in cellular reprogramming, stem cell engineering, and protein replacement therapy. Finally, future perspectives and challenges of IVT mRNA are discussed.