Novel decellularized animal conchal cartilage graft for application in human patient

Post-Implantation Inflammatory Responses to Xenogeneic Tissue-Engineered Cartilage Implanted in Rabbit Trachea: The Role of Cultured Chondrocytes in the Modification of Inflammation

Immune responses to tissue-engineered grafts made of xenogeneic materials remain poorly studied. The scope of current investigations is limited by the lack of information on orthotopically implanted grafts. A deeper understanding of these processes is of great importance since innovative surgical approaches include the implantation of xenogeneic decellularized scaffolds seeded by cells. The purpose of our work is to study the immunological features of tracheal repair during the implantation of tissue-engineered constructs based on human xenogeneic scaffolds modified via laser radiation in rabbits. The samples were stained with hematoxylin and Safranin O, and they were immunostained with antibodies against tryptase, collagen II, vimentin, and CD34. Immunological and inflammatory responses were studied by counting immune cells and evaluating blood vessels and collagen. Leukocyte-based inflammation prevailed during the implantation of decellularized unseeded scaffolds; meanwhile, plasma cells were significantly more abundant in tissue-engineered constructs. Mast cells were insignificantly more abundant in tissue-engineered construct samples. Conclusions: The seeding of decellularized xenogeneic cartilage with chondrocytes resulted in a change in immunological reactions upon implantation, and it was associated with plasma cell infiltration. Tissue-engineered grafts widely differed in design, including the type of used cells. The question of immunological response depending on the tissue-engineered graft composition requires further investigation.

Application of decellularization-recellularization technique in plastic and reconstructive surgery

ABSTRACT

In the field of plastic and reconstructive surgery, the loss of organs or tissues caused by diseases or injuries has resulted in challenges, such as donor shortage and immunosuppression. In recent years, with the development of regenerative medicine, the decellularization-recellularization strategy seems to be a promising and attractive method to resolve these difficulties. The decellularized extracellular matrix contains no cells and genetic materials, while retaining the complex ultrastructure, and it can be used as a scaffold for cell seeding and subsequent transplantation, thereby promoting the regeneration of diseased or damaged tissues and organs. This review provided an overview of decellularization-recellularization technique, and mainly concentrated on the application of decellularization-recellularization technique in the field of plastic and reconstructive surgery, including the remodeling of skin, nose, ears, face, and limbs. Finally, we proposed the challenges in and the direction of future development of decellularization-recellularization technique in plastic surgery.

The morphological postnatal development of the testis of the Nubian bucks

This study was designed to monitor the morphological development of the reproductive tract of the Nubian bucks in relation to puberty. Thirty-two Nubain male kids were used in the study. The animals were slaughtered at intervals of 2 weeks starting from 1 day old up to 24 weeks of age. Tissue samples were obtained from the testes and processed for ultrastructural studies. The boundary tissue of the newly forming seminiferous tubule adhered closely to the basal lamina. It consisted of a single continuous layer of myoid cells, the outer surface of which was covered by scattered fibroblasts. The ultrastructural study of the boundary of the seminiferous tubule revealed that it consisted of three layers; inner fibrous, middle and outer cellular. The seminiferous tubules at week one were lined by two layers of epithelia; spermatogonia and Sertoli cells in the basal layer, and primary spermatocytes in the second layer. A gradual increase in the diameter of the tubules and epithelial height continued to increase with age. Furthermore, spermatocytes number showed an increase with age. In conclusion, based on the appearance of spermatozoa in the lumina of the seminiferous tubules, puberty age was achieved between weeks 18 and 20.

Efficacy and safety of equine cartilage for rhinoplasty: a multicenter double-blind non-inferiority randomized confirmatory clinical trial

Background

The efficacy and safety of equine cartilage as a competent xenograft material for rhinoplasty were evaluated and compared to the outcomes of rhinoplasty using silicone implants.

Methods

We performed a multicenter, double-blind, non-inferiority, and randomized confirmatory study. Fifty-six patients were randomized 1:1 to the study group (using MegaCartilage-E) and control group (using silicone implants). The Rhinoplasty Outcome Evaluation (ROE) score, photo documentation, Global Aesthetic Improvement Scale (GAIS), and adverse event data were obtained until 12 months after surgery. The primary efficacy, which is the change in ROE score 6 months after surgery, was assessed in the modified intention-to-treat set. The secondary efficacy was evaluated in the per-protocol set by assessing the change in ROE score 6 and 12 months after surgery and nasofrontal angle, the height of the nasion, and GAIS 1, 6, and 12 months after surgery.

Results

The change in ROE score of the study group was non-inferior to that of the control group; it increased by 24.26±17.24 in the study group and 18.27±17.60 in the control group (p=0.213). In both groups, all secondary outcome measures increased, but there was no statistical difference. In the safety set, treatment-emergent adverse events occurred in 10 patients (35.71%) in the study group and six patients (21.43%) in the control group (p=0.237). There were 13 adverse device events in the study group and six adverse device events in the control group (p=0.515).

Conclusion

Processed equine cartilage can be used effectively and safely as xenograft material for rhinoplasty.

Biomaterial-Based Therapeutic Approaches to Osteoarthritis and Cartilage Repair Through Macrophage Polarization

There is an ever-increasing clinical and socioeconomic burden associated with cartilage lesions & osteoarthritis (OA). Its progression, chondrocyte death & hypertrophy are all facilitated by inflamed synovium & joint environment. Due to their capacity to switch between pro- & anti-inflammatory phenotypes, macrophages are increasingly being recognized as a key player in the healing process, which has been largely overlooked in the past. A biomaterial's inertness has traditionally been a goal while developing them in order to reduce the likelihood of adverse reactions from the host organism. A better knowledge of how macrophages respond to implanted materials has made it feasible to determine the biomaterial architectural parameters that control the host response & aid in effective tissue integration. Thus, this review summarizes novel therapeutic techniques for avoiding OA or increasing cartilage repair & regeneration that might be developed using new technologies tuning macrophages into desirable functional phenotypes.

Decellularization in Tissue Engineering and Regenerative Medicine: Evaluation, Modification, and Application Methods

Reproduction of different tissues using scaffolds and materials is a major element in regenerative medicine. The regeneration of whole organs with decellularized extracellular matrix (dECM) has remained a goal despite the use of these materials for different purposes. Recently, decellularization techniques have been widely used in producing scaffolds that are appropriate for regenerating damaged organs and may be able to overcome the shortage of donor organs. Decellularized ECM offers several advantages over synthetic compounds, including the preserved natural microenvironment features. Different decellularization methods have been developed, each of which is appropriate for removing cells from specific tissues under certain conditions. A variety of methods have been advanced for evaluating the decellularization process in terms of cell removal efficiency, tissue ultrastructure preservation, toxicity, biocompatibility, biodegradability, and mechanical resistance in order to enhance the efficacy of decellularization methods. Modification techniques improve the characteristics of decellularized scaffolds, making them available for the regeneration of damaged tissues. Moreover, modification of scaffolds makes them appropriate options for drug delivery, disease modeling, and improving stem cells growth and proliferation. However, considering different challenges in the way of decellularization methods and application of decellularized scaffolds, this field is constantly developing and progressively moving forward. This review has outlined recent decellularization and sterilization strategies, evaluation tests for efficient decellularization, materials processing, application, and challenges and future outlooks of decellularization in regenerative medicine and tissue engineering.

Waste-derived biomaterials as building blocks in the biomedical field

Recent developments in the biomedical arena have led to the fabrication of innovative biomaterials by utilizing bioactive molecules obtained from biological wastes released from fruit and beverage processing industries, and fish, meat, and poultry industries. These biological wastes that end up in water bodies as well as in landfills are an affluent source of animal- and plant-derived proteins, bio ceramics and polysaccharides such as collagens, gelatins, chitins, chitosans, eggshell membrane proteins, hydroxyapatites, celluloses, and pectins. These bioactive molecules have been intricately designed into scaffolds and dressing materials by utilizing advanced technologies for drug delivery, tissue engineering, and wound healing relevance. These biomaterials are environment-friendly, biodegradable, and biocompatible, and show excellent tissue regeneration attributes. Additionally, being cost-effective they can reduce the burden on the healthcare system as well as provide a sustainable solution to waste management. In this review, the current trends in the utilization of plant and animal waste-derived biomaterials in various biomedical fields are considered along with a separate section on their applications as xenografts.

Development and Characterization of Acellular Caprine Choncal Cartilage Matrix for Tissue Engineering Applications

Because of poor regenerative capabilities of cartilage, reconstruction of similar rigidity and flexibility is difficult, challenging, and restricted. The aim of the present investigation was to develop cost-effective acellular xenogeneic biomaterial as cartilage substitution. Two novel biometrics have been developed using different chemical processes (Na-deoxycholate + SDS and GndHCl + NaOH) to decellularize caprine (goat) ear cartilage and further extensively characterized before preclinical investigation. Complete cell removal was ascertained by hematoxylin and eosin staining followed by DNA estimation. No adverse effect on extracellular matrix (ECM) was found by quantifying collagen and sulfated glycosaminoglycans (sGAG) content as well as collagen, sGAG and elastin staining. Results showed no drastic changes in ECM structure apart from desired sGAG loss. Scanning electron microscopy images confirmed cellular loss and unaltered orientation. Nano-indentation study on cartilage matrices indicated interesting output showing better results among decellularized groups. Increased elastic modulus and hardness indicated better stiffness and more active energy dissipation mechanism due to decellularization. Fluid uptake and retention property remained unchanged after decellularization as analyzed by swelling behavior study. Additionally, acellular materials were confirmed to be nonreactive and nonhemolytic as assessed by in vitro hemocompatibility study. In vivo study (up to 3 months) on rabbits showed no symptoms of graft rejection/ tissue necrosis, established through postoperative histology and biochemical analyses of tissue explants. With regard to size, shape, biomechanics, source of origin and nonimmunogenic properties, these developed materials can play versatile role in biomedical/ clinical applications and pave a new insight as alternatives in cartilage reconstruction.

Surgical and Nonsurgical Management of the Nasal Skin-Soft Tissue Envelope

Management of the skin-soft tissue envelope (SSTE) in rhinoplasty is challenging and critical for the overall outcome. The preoperative identification of patients with thick or thin skin and with preexisting skin conditions may contribute significantly to the postsurgical result. Most publications and textbooks focus on the management of the osseocartilaginous framework, but the SSTE management is often not addressed in detail. However, nonsurgical treatments, such as skin preconditioning, topical steroid-injections, oral isotretinoin, and topical vitamin A derivatives, may provide strong benefits. In this article, we reviewed the literature to present a comprehensive review on the available surgical and nonsurgical approaches pre-, intra-, and postoperatively dealing with SSTE in rhinoplasty.

Fish cartilage: A promising source of biomaterial for biological scaffold fabrication in cartilage tissue engineering

Here, engineered cartilage-like scaffold using an extracellular matrix (ECM) from sturgeon fish cartilage provided a chondroinductive environment to stimulate cartilaginous matrix synthesis in human adipose stem cells (hASCs). Three dimensional porous and degradable fish cartilage ECM-derived scaffold (FCS) was produced using a protocol containing chemical decellularization, enzymatic solubilization, freeze-drying and EDC-crosslinking treatments and the effect of different ECM concentrations (10, 20, 30, and 40 mg/ml) on prepared scaffolds was investigated through physical, mechanical and biological analysis. The histological and scanning electron microscopy analysis revealed the elimination of the cell fragments and a 3-D interconnected porous structure, respectively. Cell viability assay displayed no cytotoxic effects. The prepared porous constructs of fish cartilage ECM were seeded with hASCs for 21 days and compared to collagen (Col) and collagen-10% hyaluronic acid (Col-HA) scaffolds. Cell culture results evidenced that the fabricated scaffolds could provide a proper 3-D structure to support the adhesion, proliferation and chondrogenic differentiation of hASCs considering the synthesis of specific proteins of cartilage, collagen type II (Col II) and aggrecan (ACAN). Based on the results of the present study, it can be concluded that the porous scaffold derived from fish cartilage ECM possesses an excellent potential for cartilage tissue engineering.

Decellularized xenogenic cartilage extracellular matrix (ECM) scaffolds for the reconstruction of osteochondral defects in rabbits

The use of decellularized native allogenic or xenogenic cartilaginous extracellular matrix (ECM) biomaterials is widely expanding in the fields of tissue engineering and regenerative medicine. In this study, we aimed to develop an acellular, affordable, biodegradable, easily available goat conchal cartilaginous ECM derived scaffolding biomaterial for repair and regeneration of osteochondral defects in rabbits. Cartilages harvested from freshly collected goat ears were decellularized using chemical agents, namely, hypotonic-hypertonic (HH) buffer and Triton X-100 solution, separately. The morphologies and ultrastructure orientations of the decellularized cartilages remained unaltered in spite of complete cellular loss. Furthermore, when the acellular cartilaginous ECMs were cultured with murine mesenchymal stem cells (MSCs) (C3H10T1/2 cells), cellular infiltration and proliferation were thoroughly monitored using SEM, DAPI and FDA stained images, whereas the MTT assay proved the biocompatibility of the matrices. The increasing amounts of secreted ECM proteins (collagen and sGAG) indicated successful chondrogenic differentiation of the MSCs in the presence of the treated cartilage samples. In vivo biocompatibility studies showed no significant immune response or tissue rejection in the treated samples but tissue necrosis in control samples after 3 months. Upon implantation of the constructs in rabbits' osteochondral defects for 3 months, the histological and micro-CT evaluation revealed significant enhancement and regeneration of neocartilage and subchondral bony tissues. The IGF-1 loaded cartilaginous constructs showed comparatively better healing response after 3 months. Our results showed that decellularized xenogenic cartilaginous biomaterials preserved the bioactivity and integrity of the matrices that also favored in vitro stem cell proliferation and chondrogenic differentiation and enabled osteochondral regeneration, thus paving a new way for articular cartilage reconstruction.

Tissue-derived decellularized extracellular matrices toward cartilage repair and regeneration

The inability of cartilage tissue to self-heal due to its avascular nature often leads to conditions such as osteoarthritis, traumatic rupture of cartilage, and osteochondrosis. The cartilage provides cushioning effects between the joints and avoids bone frictions. The extracellular matrix (ECM) of cartilage consists predominantly of collagens, elastin, proteoglycans and glycoproteins. A number of tissue engineered ECM derived biological scaffolds and matrices are available for cartilage regeneration. The decellularized tissues provide appropriate bioactive cues in the absence of cellular components, hence avoiding immunological issue. However, the decellularization process involves several cellular disruption techniques that may alter the ECM architecture affecting bioactivity. Therefore, development of cell-free cartilage biomaterials with unaltered ECM integrity and bioactivity is of paramount necessity by smart selection of modified techniques and agents. Herein, we described about various decellularization methods, agents, techniques, and their applications in tissue/cartilage decellularization. It also contemplates various difficulties and future perspectives to troubleshoot the existing obstructions in tissue-derived cartilage matrices and their applications.