Autotransplantation of Monkey Ear Perichondrium-Derived Progenitor Cells for Cartilage Reconstruction

Suitability of Ex Vivo-Expanded Microtic Perichondrocytes for Auricular Reconstruction

Tissue engineering (TE) techniques offer solutions for tissue regeneration but require large quantities of cells. For microtia patients, TE methods represent a unique opportunity for therapies with low donor-site morbidity and reliance on the surgeon's individual expertise. Microtia-derived chondrocytes and perichondrocytes are considered a valuable cell source for autologous reconstruction of the pinna. The aim of this study was to investigate the suitability of perichondrocytes from microtia patients for autologous reconstruction in comparison to healthy perichondrocytes and microtia chondrocytes. Perichondrocytes were isolated via two different methods: explant culture and enzymatic digestion. The isolated cells were analyzed in vitro for their chondrogenic cell properties. We examined migration activity, colony-forming ability, expression of mesenchymal stem cell markers, and gene expression profile. We found that microtic perichondrocytes exhibit similar chondrogenic properties compared to chondrocytes in vitro. We investigated the behavior in three-dimensional cell cultures (spheroids and scaffold-based 3D cell cultures) and assessed the expression of cartilage-specific proteins via immunohistochemistry, e.g., collagen II, which was detected in all samples. Our results show that perichondrocytes from microtia patients are comparable to healthy perichondrocytes and chondrocytes in terms of chondrogenic cell properties and could therefore be a promising cell source for auricular reconstruction.

Hypoxia Differentially Affects Chondrogenic Differentiation of Progenitor Cells from Different Origins

Background and Objectives

Ear cartilage malformations are commonly encountered problems in reconstructive surgery, since cartilage has low self-regenerating capacity. Malformations that impose psychological and social burden on one's life are currently treated using ear prosthesis, synthetic implants or autologous flaps from rib cartilage. These approaches are challenging because not only they request high surgical expertise, but also they lack flexibility and induce severe donor-site morbidity. Through the last decade, tissue engineering gained attention where it aims at regenerating human tissues or organs in order to restore normal functions. This technique consists of three main elements, cells, growth factors, and above all, a scaffold that supports cells and guides their behavior. Several studies have investigated different scaffolds prepared from both synthetic or natural materials and their effects on cellular differentiation and behavior.

Methods and Results

In this study, we investigated a natural scaffold (alginate) as tridimensional hydrogel seeded with progenitors from different origins such as bone marrow, perichondrium and dental pulp. In contact with the scaffold, these cells remained viable and were able to differentiate into chondrocytes when cultured in vitro. Quantitative and qualitative results show the presence of different chondrogenic markers as well as elastic ones for the purpose of ear cartilage, upon different culture conditions.

Conclusions

We confirmed that auricular perichondrial cells outperform other cells to produce chondrogenic tissue in normal oxygen levels and we report for the first time the effect of hypoxia on these cells. Our results provide updates for cartilage engineering for future clinical applications.

Regeneration of Rabbit Auricular Cartilage After the Intravenous Stem Cell Injection

Background

The restoration of auricular cartilage is a major problem of otolaryngology. The low regenerative capacity of cartilage requires alternative approaches such as cell and tissue engineering. Stem cells are one of the ways to repair auricular cartilage damages. The aim of the investigation was the regeneration of an artificial defect of the auricular cartilage of rabbits after the intravenous injection of stem cells.

Materials and Methods

The study was carried out on rabbits. A narrow strip of auricular cartilage was surgically removed. A previously prepared suspension of homologous mesenchymal stem cells (5 million) in 0.5 ml physiological solution was injected into the vein of the opposite ear. Tissue samples from the site of the injury were collected after 1, 2, and 3 months. Histological examinations of the tissues were carried out after staining with fuchsin-eosin, azure II-eosin, and according to Weigert. In addition, the amount of interleukin-6 (IL-6) and the transforming growth factor β1 (TGF-β1) in the blood serum were determined.

Results

The main method of healing is the formation of a connective tissue scar. Yret, an increase of the number of fibroblasts and single islands of the newly formed auricular cartilage was found, which indicates the migration of the injected stem cells to the site of the damage and settling there. The intravenous injection of stem cells did not affect the secretion of pro-inflammatory IL-6, but significantly increased the amount of TGF-β1.

Conclusions

We assume that regenerative processes were stimulated. Nevertheless, they were aimed at quickly restoring the tissue integrity through the typical stages of scar formation. The restoration of cartilage integrity requires additional regulatory factors which will determine the chondrogenic differentiation of stem cells.

The application and progress of stem cells in auricular cartilage regeneration: a systematic review

Background: The treatment of microtia or acquired ear deformities by surgery is a significant challenge for plastic and ENT surgeons; one of the most difficult points is constructing the scaffold for auricular reconstruction. As a type of cell with multiple differentiation potentials, stem cells play an essential role in the construction of cartilage scaffolds, and therefore have received widespread attention in ear reconstructive research. Methods: A literature search was conducted for peer-reviewed articles between 2005 and 2023 with the following keywords: stem cells; auricular cartilage; ear cartilage; conchal cartilage; auricular reconstruction, regeneration, and reparation of chondrocytes; tissue engineering in the following databases: PubMed, MEDLINE, Cochrane, and Ovid. Results: Thirty-three research articles were finally selected and their main characteristics were summarized. Adipose-derived stem cells (ADSCs), bone marrow mesenchymal stem cells (BMMSCs), perichondrial stem/progenitor cells (PPCs), and cartilage stem/progenitor cells (CSPCs) were mainly used in chondrocyte regeneration. Injecting the stem cells into the cartilage niche directly, co-culturing the stem cells with the auricular cartilage cells, and inducing the cells in the chondrogenic medium in vitro were the main methods that have been demonstrated in the studies. The chondrogenic ability of these cells was observed in vitro, and they also maintained good elasticity and morphology after implantation in vivo for a period of time. Conclusion: ADSC, BMMSC, PPC, and CSPC were the main stem cells that have been researched in craniofacial cartilage reconstruction, the regenerative cartilage performed highly similar to normal cartilage, and the test of AGA and type II collagen content also proved the cartilage property of the neo-cartilage. However, stem cell reconstruction of the auricle is still in the initial stage of animal experiments, transplantation with such scaffolds in large animals is still lacking, and there is still a long way to go.

Experimental Study on the Biological Outcome of Auricular Cartilage and Costal Cartilage at Different Time Periods After Autologous Cartilage Rhinoplasty

Since autologous cartilage is a good transplant material, it is widely used in various fields of clinical medicine. In this study, we collected clinical specimens obtained at different numbers of years after transplantation and used histologic staining to explore the post-transplantation changes in auricular cartilage and costal cartilage. A retrospective analysis was performed on patients who underwent primary autologous cartilage rhinoplasty and secondary rhinoplasty from 2017 to 2021, and the remaining autologous cartilage tissue after surgery was used for histologic testing. As time progressed after transplantation, the density of costal chondrocytes decreased first and then increased, while the secretion of type II collagen and extracellular matrix both decreased slightly. There was a clear boundary between the cartilage tissue and the surrounding connective tissue, and there was no ingrowth of blood vessels in the cartilage. Auricular cartilage showed a decrease in the integrity of the matrix edge. Moreover, local fibrosis was visible, and vascular ingrowth was observed at the edge of the cartilage. The content of type II collagen first increased and then decreased, and the cell secretion function was lower than that of normal chondrocytes. The results of the study suggest that the histologic outcome of elastic cartilage after transplantation is significantly different from that of hyaline cartilage. Moreover, costal cartilage was more stable than auricular cartilage after transplantation.

Reconstruction of the distal radioulnar joint with rib perichondrium - midterm follow-up

Background

Reconstruction of an osteoarthritic distal radioulnar joint (DRUJ) in patients with high physical demands and a long lifetime expectancy is challenging. A variety of methods like implant surgery and salvage procedures as partial or total ulnar head resection and the Sauve-Kapandji procedure are reasonable options in the elderly patient but not in young individuals since it often compromises manual power and stability and may cause impingement problems. Reconstruction of the DRUJ with rib perichondrium is a new treatment option with promising short-term outcome. The aim the present study was to investigate if the outcome is consistent over time.

Methods

Four female patients with a mean age of 40.5 years suffered severe unilateral osteoarthritis in the DRUJ. They underwent reconstruction of the joint with rib perichondrium transplants. Preoperatively, mean pain under manual load was 8.5 (range 7–10) and 4.2 (range 2–5) at rest, using the visual analogue scale (VAS). Range of motion (ROM) in forearm rotation was on average 118° and grip strength was 86% in comparison to the contralateral hand. The outcome was assessed at a clinical follow-up in 2016, measuring ROM, grip-strength, pain at rest and under manual load and DASH-score. Radiological examination was performed. An additional follow-up by letter was performed in 2021 using a patient-reported-outcome survey (PROS). The patients were asked to grade the ROM and grip-strength as changed or unchanged in comparison to the clinical follow-up in 2016.

Results

At clinical follow-up at a mean of 3.1 years (range 1–5) after surgery, pain level had decreased to VAS 1.5 (0–5) under load and all patients were pain free at rest. Forearm rotation was on average 156° (range 100–180) and grip strength was 97% of the unoperated hand. The mean DASH-score was 14.4 (0–45). An additional follow-up by letter was conducted at a mean of 7.5 years (5.5–9.5) after surgery. ROM and grip strength were reported as unchanged by all patients in relation to the previous clinical follow-up. No additional surgery or complications were reported.

Conclusion

Reconstruction of the osteoarthritic DRU-joint with rib perichondrium transplantation can provide good clinical outcome with perseverance over time.

Level of evidence

IV.

Rat perichondrium transplanted to articular cartilage defects forms articular-like, hyaline cartilage

OBJECTIVE

Perichondrium autotransplants have been used to reconstruct articular surfaces destroyed by infection or trauma. However, the role of the transplanted perichondrium in the healing of resurfaced joints has not been investigated.

DESIGN

Perichondrial and periosteal tissues were harvested from rats hemizygous for a ubiquitously expressed enhanced green fluorescent protein (EGFP) transgene and transplanted into full-thickness articular cartilage defects at the trochlear groove of distal femur in wild-type littermates. As an additional control, cartilage defects were left without a transplant (no transplant control). Distal femurs were collected 3, 14, 56, 112 days after surgery.

RESULTS

Tracing of transplanted cells showed that both perichondrium and periosteum transplant-derived cells made up the large majority of the cells in the regenerated joint surfaces. Perichondrium transplants contained SOX9 positive cells and with time differentiated into a hyaline cartilage that expanded and filled out the defects with Col2a1-positive and Col1a1-negative chondrocytes and a matrix rich in proteoglycans. At later timepoints the cartilaginous perichondrium transplants were actively remodeled into bone at the transplant-bone interface and at post-surgery day 112 EGFP-positive perichondrium cells at the articular surface were positive for Prg4. Periosteum transplants initially lacked SOX9 expression and despite a transient increase in SOX9 expression and chondrogenic differentiation, remained Col1a1 positive, and were continuously thinning as periosteum-derived cells were incorporated into the subchondral compartment.

CONCLUSIONS

Perichondrium and periosteum transplanted to articular cartilage defects did not just stimulate regeneration but were themselves transformed into cartilaginous articular surfaces. Perichondrium transplants developed into an articular-like, hyaline cartilage, whereas periosteum transplants appeared to produce a less resilient fibro-cartilage.

Recent update on craniofacial tissue engineering

The craniofacial region consists of several different tissue types. These tissues are quite commonly affected by traumatic/pathologic tissue loss which has so far been traditionally treated by grafting procedures. With the complications and drawbacks of grafting procedures, the emerging field of regenerative medicine has proved potential. Tissue engineering advancements and the application in the craniofacial region is quickly gaining momentum although most research is still at early in vitro/in vivo stages. We aim to provide an overview on where research stands now in tissue engineering of craniofacial tissue; namely bone, cartilage muscle, skin, periodontal ligament, and mucosa. Abstracts and full-text English articles discussing techniques used for tissue engineering/regeneration of these tissue types were summarized in this article. The future perspectives and how current technological advancements and different material applications are enhancing tissue engineering procedures are also highlighted. Clinically, patients with craniofacial defects need hybrid reconstruction techniques to overcome the complexity of these defects. Cost-effectiveness and cost-efficiency are also required in such defects. The results of the studies covered in this review confirm the potential of craniofacial tissue engineering strategies as an alternative to avoid the problems of currently employed techniques. Furthermore, 3D printing advances may allow for fabrication of patient-specific tissue engineered constructs which should improve post-operative esthetic results of reconstruction. There are on the other hand still many challenges that clearly require further research in order to catch up with engineering of other parts of the human body.

Tissue engineering applications in otolaryngology-The state of translation

While tissue engineering holds significant potential to address current limitations in reconstructive surgery of the head and neck, few constructs have made their way into routine clinical use. In this review, we aim to appraise the state of head and neck tissue engineering over the past five years, with a specific focus on otologic, nasal, craniofacial bone, and laryngotracheal applications. A comprehensive scoping search of the PubMed database was performed and over 2000 article hits were returned with 290 articles included in the final review. These publications have addressed the hallmark characteristics of tissue engineering (cellular source, scaffold, and growth signaling) for head and neck anatomical sites. While there have been promising reports of effective tissue engineered interventions in small groups of human patients, the majority of research remains constrained to in vitro and in vivo studies aimed at furthering the understanding of the biological processes involved in tissue engineering. Further, differences in functional and cosmetic properties of the ear, nose, airway, and craniofacial bone affect the emphasis of investigation at each site. While otolaryngologists currently play a role in tissue engineering translational research, continued multidisciplinary efforts will likely be required to push the state of translation towards tissue-engineered constructs available for routine clinical use.

LEVEL OF EVIDENCE

NA.

Modeling Normal and Pathological Ear Cartilage in vitro Using Somatic Stem Cells in Three-Dimensional Culture

Microtia (underdeveloped ear) is a rare congenital dysmorphology affecting the development of the outer ear. Although human microtic cartilage has not been fully characterized, chondrogenic cells derived from this tissue have been proposed as a suitable source for autologous auricular reconstruction. The aim of this study was to further characterize native microtic cartilage and investigate the properties of cartilage stem/progenitor cells (CSPCs) derived from it. Two-dimensional (2D) systems are most commonly used to assess the chondrogenic potential of somatic stem cells in vitro, but limit cell interactions and differentiation. Hence here we investigated the behavior of microtic CSPCs in three-dimensional spheroid cultures. Remarkable similarities between human microtic cartilages from five patients, as compared to normal cartilage, were observed notwithstanding possibly different etiologies of the disease. Native microtic cartilage displayed poorly defined perichondrium and hyper-cellularity, an immature phenotype that resembled that of the normal developing human auricular cartilage we studied in parallel. Crucially, our analysis of microtic ears revealed for the first time that, unlike normal cartilage, microtic cartilages are vascularized. Importantly, CSPCs isolated from human microtic and normal ear cartilages were found to recapitulate many characteristics of pathological and healthy tissues, respectively, when allowed to differentiate as spheroids, but not in monolayer cultures. Noteworthily, starting from initially homogeneous cell pellets, CSPC spheroids spontaneously underwent a maturation process in culture, and formed two regions (inner and outer region) separated by a boundary, with distinct cell types that differed in chondrogenic commitment as indicated by expression of chondrogenic markers. Compared to normal ear-derived spheroids, microtic spheroids were asymmetric, hyper-cellularized and the inner and outer regions did not develop properly. Hence, their organization resembled that of native microtic cartilage. Together, our results identify novel features of microtic ears and highlight the importance of 3D self-organizing in vitro systems for better understanding somatic stem cell behavior and disease modeling. Our observations of ear-derived chondrogenic stem cell behavior have implications for choice of cells for tissue engineered reconstructive purposes and for modeling the etiopathogenesis of microtia.

Reconstruction of finger joints using autologous rib perichondrium - an observational study at a single Centre with a median follow-up of 37 years

BACKGROUND

Gratifying long-term results are difficult to achieve when reconstructing osteoarthritic finger joints. Implant surgery is the most commonly used method to restore function and dexterity. However, all types of implant have disadvantages and may be a less favorable option in some cases, especially in young patients with a long expected lifetime and high demands on manual load. Implant related complications as loosening, instability, subsidence and stiffness are the main concerns. In this context, joint reconstruction using rib perichondrium might be a reasonable alternative in selected cases. The aim of the study was to evaluate the long-term results of finger joint reconstruction using rib perichondrial transplantation.

METHODS

The study group (n = 11) consisted of eight individuals reconstructed in the proximal interphalangeal (PIP) joints and three reconstructed in the metacarpophalangeal (MCP) joints during 1974-1981. All patients were evaluated at clinical visits (median: 37 years after perichondrial transplantation, range: 34-41 years) using radiographs, disability in arm-shoulder-hand (DASH) score, Visual Analog Scale (VAS), range-of-motion (ROM) and manual strength (JAMAR).

RESULTS

None of the 11 patients had undergone additional surgery. All of the PIP-joints (n = 8) were almost pain-free at activity (VAS 0,6) (range 0-4), had an average range-of-motion of 41 degrees (range 5-80) and a mean DASH-score of 8,3 (range 1-51). The mean strength was 41 kg compared to 44 kg in the contralateral hand (93%). The three MCP joints were almost pain-free at activity (VAS 0,7), (range 0-1). The ROM was on average 80 degrees (range 70-90) and the mean DASH-score was 2 (range 1-3). The mean strength was 43 kg compared to 53 kg in the contralateral hand (81%).

CONCLUSIONS

Perichondrium transplants restored injured PIP and MCP joints that remained essentially pain-free and mostly well-functioning without need for additional surgeries up to 41 years after the procedure. Additional studies are needed to evaluate long-term results in comparison to modern implants and to better describe the factors that determine the outcome of these procedures.

LEVEL OF EVIDENCE

Level IV, Therapeutic Study.

Animal Models of Osteochondral Defect for Testing Biomaterials

The treatment of osteochondral defects (OCD) remains a great challenge in orthopaedics. Tissue engineering holds a good promise for regeneration of OCD. In the light of tissue engineering, it is critical to establish an appropriate animal model to evaluate the degradability, biocompatibility, and interaction of implanted biomaterials with host bone/cartilage tissues for OCD repair in vivo. Currently, model animals that are commonly deployed to create osteochondral lesions range from rats, rabbits, dogs, pigs, goats, and sheep horses to nonhuman primates. It is essential to understand the advantages and disadvantages of each animal model in terms of the accuracy and effectiveness of the experiment. Therefore, this review aims to introduce the common animal models of OCD for testing biomaterials and to discuss their applications in translational research. In addition, we have reviewed surgical protocols for establishing OCD models and biomaterials that promote osteochondral regeneration. For small animals, the non-load-bearing region such as the groove of femoral condyle is commonly chosen for testing degradation, biocompatibility, and interaction of implanted biomaterials with host tissues. For large animals, closer to clinical application, the load-bearing region (medial femoral condyle) is chosen for testing the durability and healing outcome of biomaterials. This review provides an important reference for selecting a suitable animal model for the development of new strategies for osteochondral regeneration.

Therapeutic "Tool" in Reconstruction and Regeneration of Tissue Engineering for Osteochondral Repair

Repairing osteochondral defects to restore joint function is a major challenge in regenerative medicine. However, with recent advances in tissue engineering, the development of potential treatments is promising. In recent years, in addition to single-layer scaffolds, double-layer or multilayer scaffolds have been prepared to mimic the structure of articular cartilage and subchondral bone for osteochondral repair. Although there are a range of different cells such as umbilical cord stem cells, bone marrow mesenchyml stem cell, and others that can be used, the availability, ease of preparation, and the osteogenic and chondrogenic capacity of these cells are important factors that will influence its selection for tissue engineering. Furthermore, appropriate cell proliferation and differentiation of these cells is also key for the optimal repair of osteochondral defects. The development of bioreactors has enhanced methods to stimulate the proliferation and differentiation of cells. In this review, we summarize the recent advances in tissue engineering, including the development of layered scaffolds, cells, and bioreactors that have changed the approach towards the development of novel treatments for osteochondral repair.

Head to Knee: Cranial Neural Crest-Derived Cells as Promising Candidates for Human Cartilage Repair

A large array of therapeutic procedures is available to treat cartilage disorders caused by trauma or inflammatory disease. Most are invasive and may result in treatment failure or development of osteoarthritis due to extensive cartilage damage from repeated surgery. Despite encouraging results of early cell therapy trials that used chondrocytes collected during arthroscopic surgery, these approaches have serious disadvantages, including morbidity associated with cell harvesting and low predictive clinical outcomes. To overcome these limitations, adult stem cells derived from bone marrow and subsequently from other tissues are now considered as preferred sources of cells for cartilage regeneration. Moreover, with new evidence showing that the choice of cell source is one of the most important factors for successful cell therapy, there is growing interest in neural crest-derived cells in both the research and clinical communities. Neural crest-derived cells such as nasal chondrocytes and oral stem cells that exhibit chondrocyte-like properties seem particularly promising in cartilage repair. Here, we review the types of cells currently available for cartilage cell therapy, including articular chondrocytes and various mesenchymal stem cells, and then highlight recent developments in the use of neural crest-derived chondrocytes and oral stem cells for repair of cartilage lesions.

The Ex Vivo Time of Fresh Autologous Cartilage Before Transplantation and Cartilage Absorption Degree

OBJECTIVE

This study aims to determine the relationship between the time of autogenous cartilage in vitro and the degree of absorption in animal experiments.

METHODS

New Zealand white rabbits were randomly divided into 3 groups according to the time of cartilage in vitro: 1-hour group, 2-hour group, and 3-hour group. A volume of ear cartilage was taken and transplanted into the back, according to the group. After 1 month, the volume was taken out and remeasured. Then, these were compared by scanning electron microscopy and hematoxylin and eosin staining.

RESULTS

The cartilage bulk absorption level of different groups is different (P < 0.05). There was statistical significance when the 3-hour group was compared with the other 2 groups (P < 0.05). This shows that cartilage volume absorption level becomes higher after 3 hours. Scanning electron microscopy revealed that before and after transplantation, the arrangement of collagen fibers and the gap between these fibers changed. Hematoxylin and eosin staining revealed that there were some morphological changes in chondrocytes, and the degree of chondrocyte apoptosis increased with time, which was accompanied by granulation tissue formation. In addition, the cartilage tissue survived after transplantation.

CONCLUSION

The change in cartilage volume was more obvious after 3 hours of autogenous fresh cartilage transplantation, when compared with that of the first 2 hours. The longer the time of light microscopy was, the longer the apoptosis of cartilage cells, the more serious the destruction of collagen fibers and the cartilage matrix, and the greater the absorption of cartilage and the new chondrocytes.

Angiogenesis after administration of basic fibroblast growth factor induces proliferation and differentiation of mesenchymal stem cells in elastic perichondrium in an in vivo model: mini review of three sequential republication-abridged reports

To date, studies on mesenchymal tissue stem cells (MSCs) in the perichondrium have focused on in vitro analysis, and the dynamics of cartilage regeneration from the perichondrium in vivo remain largely unknown. We have attempted to apply cell and tissue engineering methodology for ear reconstruction using cultured chondrocytes. We hypothesized that by inducing angiogenesis with basic fibroblast growth factor (bFGF), MSCs or cartilage precursor cells would proliferate and differentiate into cartilage in vivo and that the regenerated cartilage would maintain its morphology over an extended period. As a result of a single administration of bFGF to the perichondrium, cartilage tissue formed and proliferated while maintaining its morphology for at least 3 months. By day 3 post bFGF treatment, inflammatory cells, primarily comprising mononuclear cells, migrated to the perichondrial region, and the proliferation of matrix metalloproteinase 1 positive cells peaked. During week 1, the perichondrium thickened and proliferation of vascular endothelial cells was noted, along with an increase in the number of CD44-positive and CD90-positive cartilage MSCs/progenitor cells. Neocartilage was formed after 2 weeks, and hypertrophied mature cartilage was formed and maintained after 3 months. Proliferation of the perichondrium and cartilage was bFGF concentration-dependent and was inhibited by neutralizing antibodies. Angiogenesis induction by bFGF was blocked by the administration of an angiogenesis inhibitor, preventing perichondrium proliferation and neocartilage formation. These results suggested that angiogenesis may be important for the induction and differentiation of MSCs/cartilage precursor cells in vivo, and that morphological changes, once occurring, are maintained.