Possibilidade de ossificação intracondral dirigida a partir de uma matriz óssea com titânio

In the present study, the relation between bone, cartilage and titanium was analyzed. According to the established methodology, homogeneous cartilage grafts conserved in alcohol 100 GL for 7 days were used, after the fixation of a homologous cartilage graft above the bone cortical of a rat femur (Rattus novergicus var. Albinus rodentia mammalia cepa Wistar), using a titanium screw implant. The animals were sacrificed at 10, 20, 30 and 60 days after surgery. To the histological examination, in hematoxillin and eosin sections, intrachondral bone neoformation could be observed since cortical surface, with possibility of complete substitution of the cartilage graft by bone, with similar volume and shape. In this experimental study we concluded that the homogeneous cartilage conserved can be used as graft not only for tissue substitution but also as an inductor of bone growth in rats.

Comparative study of tympanoplasty type I using periosteum versus tragal cartilage with perichondrium

Background Various grafting materials and different techniques have been used for myringoplasty. The aim of the study was to compare the result of tympanoplasty in patients with safe-type chronic suppurative otitis media using periosteum versus tragal cartilage with perichondrium grafts through pre- and postoperative clinical and audiological evaluation. Results There was statistically significant difference for mean air-bone gap for group A (23.4 dB ± 0.03 SD) when compared to group B (19.4 dB ± 4.2 SD) with P value 0.103. Also, there was statistically significant difference in the hearing gain in group A after 6 months (25.53 dB ± 6.26 SD) when compared to group B (19.63 dB ± 9.76 SD) and the P value was 0.003. Graft taken was superior in the periosteal group (95%), compared to the cartilage grafts (90%). Conclusion Tympanoplasty with periosteal graft showed better hearing results and high rates of graft taken than tragal cartilage grafts.

The Effect of Perichondrium and Graft Modification on the Viability of Conchal Cartilage Graft: An Experimental Study in Rabbit

Objective: Cartilage grafts are widely used in reconstructing nasal deformity for structural and aesthetic purposes. Despite being immunologically privileged, cartilage grafts are susceptible to volume loss with high risk of resorption over time. Therefore, experts opt for cartilage handling modification to resolve this issue through graft dicing, wrapping, or perichondrium preservation. This study will evaluate the effect cartilage graft preparations on graft viability. Design: Single-randomized post-test-only study design. Setting: Animal Hospital at Bogor Agricultural Institute. Participants: Six New Zealand, male, Hycole rabbits. Intervention: Conchal cartilage grafts were retrieved from 6 experimental rabbits and distributed into 3 treatment groups: diced cartilage graft (DC; control), one-sided perichondrium-attached scored cartilage (OPSC), and tube-shaped perichondrium-wrapped diced cartilage (TPDC). Main Outcome Measures: Macroscopic (weight and contour) and microscopic (chondroblast proliferation, graft thickness, apoptotic cells) evaluation through histological measures were recorded on week 12. Statistical analysis was done to compare between groups. Results: Diced cartilage and OPSC groups showed significant weight changes on week 12 ( P < .05) with OPSC presenting with the biggest difference. Diced cartilage and OPSC group showed moderate cell proliferation on week 12 while TPDC displayed most abundant apoptotic cells (5.8%; P < .05). Diced cartilage group had the highest cartilage thickness ratio ( P < .05). Discussion: Bare DC technique promoted graft thickness while perichondrium-attached scored cartilage showed the most abundant chondroblast proliferation and the least apoptotic cells. Perichondrium contributes to enhanced new cartilage formation. Conclusion: Diced cartilage graft is suitable for masking irregularity and volume augmentation, while perichondrium-attached cartilage graft is better for structural support in nasal reconstruction.

In Vitro Effects of Bupivacaine on the Viability and Mechanics of Native and Engineered Cartilage Grafts

Background: Although the toxic effects of bupivacaine on chondrocyte monolayer culture have been well described, its cellular and mechanical effects on native and engineered articular cartilage remain unclear. For the repair of articular cartilage defects, fresh autologous and allogenic cartilage grafts are commonly used, and engineered cell-based therapies are emerging. The outcome of grafting therapies aimed at repairing damaged cartilage relies largely on maintaining proper viability and mechanical suitability of the donor tissues. Purpose: To investigate the in vitro effects of single bupivacaine exposure on the viability and mechanics of 2 cartilage graft types: native articular cartilage and engineered neocartilage. Study Design: Controlled laboratory study. Methods: Articular cartilage explants were harvested from the bovine stifle femoral condyles, and neocartilage constructs were engineered from bovine stifle chondrocytes using the self-assembling process, a scaffold-free approach to engineer cartilage tissue. Both explants and neocartilage were exposed to chondrogenic medium containing a clinically applicable bolus of 0.5%, 0.25%, or 0% (control) bupivacaine for 1 hour, followed by fresh medium wash and exchange. Cell viability and matrix content (collagen and glycosaminoglycan) were assessed at t = 24 hours after treatment, and compressive mechanical properties were assessed with creep indentation testing at t = 5 to 6 days after treatment. Results: Single bupivacaine exposure was chondrotoxic in both explants and neocartilage, with 0.5% bupivacaine causing a significant decrease in chondrocyte viability compared with the control condition (55.0% ± 13.4% vs 71.9% ± 13.5%; P < .001). Bupivacaine had no significant effect on matrix content for either tissue type. There was significant weakening of the mechanical properties in the neocartilage when treated with 0.5% bupivacaine compared with control, with decreased aggregate modulus (415.8 ± 155.1 vs 660.3 ± 145.8 kPa; P = .003), decreased shear modulus (143.2 ± 14.0 vs 266.5 ± 89.2 kPa; P = .002), and increased permeability (14.7 ± 8.1 vs 6.6 ± 1.7 × 10−15 m4/Ns; P = .009). Bupivacaine exposure did not have a significant effect on the mechanical properties of native cartilage explants. Conclusion: Single bupivacaine exposure resulted in significant chondrotoxicity in native explants and neocartilage and significant weakening of mechanical properties of neocartilage. The presence of abundant extracellular matrix does not appear to confer any additional resistance to the toxic effects of bupivacaine. Clinical Relevance: Clinicians should be judicious regarding the use of intra-articular bupivacaine in the setting of articular cartilage repair.

Human Chondrocytes from Human Adipose Tissue-Derived Mesenchymal Stem Cells Seeded on a Dermal-Derived Collagen Matrix Sheet: Our Preliminary Results for a Ready to Go Biotechnological Cartilage Graft in Clinical Practice

Background. The articular cartilage is unique in that it contains only a single type of cell and shows poor ability for spontaneous healing. Cartilage tissue engineering which uses mesenchymal stem cells (MSCs) and adipose tissue-derived mesenchymal stem cells (AT-MSCs) is considered an attractive treatment for cartilage lesions and osteoarthritis. The establishment of cartilage regenerative medicine is an important clinical issue, but the search for cell sources able to restore cartilage integrity proves to be challenging. The aim of this study was to create cartilage grafts from the combination of AT-MSCs and collagen substrates. Methods. Mesenchymal stem cells were obtained from human donors’ adipose tissue, and collagen scaffold, obtained from human skin and cleaned from blood vessels, adipose tissues, and debris, which only preserve dermis and epidermis, were seeded and cultured on collagen substrates and differentiated to chondrocytes. The obtained chondrocyte extracellular matrix of cartilage was then evaluated for the expression of chondrocyte-/cartilage-specific markers, the Cartilage Oligomeric Matrix Protein (COMP), collagen X, alpha-1 polypeptide (COL10A1), and the Collagen II, Human Tagged ORF Clone (COL2A1) by using the reverse transcription polymerase chain reaction (RT-PCR). Results. Our findings have shown that the dermal collagen may exert important effects on the quality of in vitro expanded chondrocytes, leading in this way that the influence of collagen skin matrix helps to produce highly active and functional chondrocytes for long-term cartilage tissue regeneration. Conclusion. This research opens up the possibility of generating cartilage grafts with the precise purpose of improving the existing limitation in current clinical procedures.