The clot thickens: Autologous and allogeneic fibrin sealants are mechanically equivalent in an ex vivo model of cartilage repair

Mechanical Evaluation of Commercially Available Fibrin Sealants for Cartilage Repair

OBJECTIVE

Fibrin sealants are routinely used for intra-articular surgical fixation of cartilage fragments and implants. However, the mechanical properties of fibrin sealants in the context of cartilage repair are unknown. The purpose of this study was to characterize the adhesive and frictional properties of fibrin sealants using an ex vivo model.

DESIGN

Native bovine cartilage-bone composites were assembled with a single application of Tisseel or Vistaseal. Composites were tested in tension and lap shear. In addition, the coefficient of friction (COF) was measured in a native cartilage annulus model alone and with minced cartilage. Finally, the effect of a double application of fibrin sealant was evaluated.

RESULTS

There were no significant differences in tensile modulus, ultimate tensile strength (UTS), shear modulus, or ultimate shear strength (USS) between the 2 fibrin sealants. Both fibrin sealants demonstrated a UTS and USS of <8 and <30 kPa, respectively. There were no differences in COF between the sealants when tested alone or with minced cartilage. A double application of fibrin sealant did not alter the mechanical properties compared with a single application of fibrin sealant.

CONCLUSIONS

Fibrin sealant adhesive properties are not affected by the sealant type studied or the number of applications in a bovine cartilage-bone model. Fibrin sealant tribological properties are not affected by sealant type or the addition of minced cartilage. The adhesive properties of Tisseel and Vistaseal were less than those desired for the in vivo fixation of cartilage repair implants. These findings motivate the development of an improved cartilage-specific adhesive for cartilage repair applications.

A Novel Fibrin Matrix Derived from Platelet-Rich Plasma: Protocol and Characterization

Although fibrin matrices derived from Platelet-Rich Plasma (PRP) are widely used in regenerative medicine, they have some limitations that can hinder their application. Modifying the composition of the PRP-derived fibrin matrix may improve its properties, making it suitable for certain medical uses. Three types of fibrin matrices were obtained: a PRP-derived fibrin matrix (FM), a PRP-derived fibrin matrix with a high fibrinogen content and platelets (FM-HFP) and a PRP-derived fibrin matrix with a high fibrinogen content (FM-HF). The fibrinogen levels, biomechanical properties and cell behavior were analyzed. The presence of platelets in the FM-HFP generated an inconsistent fibrin matrix that was discarded for the rest of the analysis. The fibrinogen levels in the FM-FH were higher than those in the FM (p < 0.0001), with a concentration factor of 6.86 ± 1.81. The values of clotting and swelling achieved using the FM-HF were higher (p < 0.0001), with less clot shrinkage (p < 0.0001). The FM had a significantly higher stiffness and turned out to be the most adherent composition (p = 0.027). In terms of cell viability, the FM-HF showed less cell proliferation but higher live/dead ratio values (p < 0.01). The increased fibrinogen and platelet removal in the FM-HF improved its adhesion and other biomechanical properties without affecting cell viability.

Biochemical and biomechanical characterization of an autologous protein-based fibrin sealant for regenerative medicine

Accidental events or surgical procedures usually lead to tissue injury. Fibrin sealants have proven to optimize the healing process but have some drawbacks due to their allogeneic nature. Autologous fibrin sealants present several advantages. The aim of this study is to evaluate the performance of a new autologous fibrin sealant based on Endoret®PRGF® technology (E-sealant). One of the most widely used commercial fibrin sealants (Tisseel®) was included as comparative Control. E-sealant´s hematological and biological properties were characterized. The coagulation kinetics and the microstructure were compared. Their rheological profile and biomechanical behavior were also recorded. Finally, the swelling/shrinkage capacity and the enzymatic degradation of adhesives were determined. E-sealant presented a moderate platelet concentration and physiological levels of fibrinogen and thrombin. It clotted 30 s after activation. The microstructure of E-sealant showed a homogeneous fibrillar scaffold with numerous and scattered platelet aggregates. In contrast, Control presented absence of blood cells and amorphous protein deposits. Although in different order of magnitude, both adhesives had similar rheological profiles and viscoelasticity. Control showed a higher hardness but both adhesives presented a pseudoplastic hydrogel nature with a shear thinning behavior. Regarding their adhesiveness, E-sealant presented a higher tensile strength before cohesive failure but their elastic stretching capacity and maximum elongation was similar. While E-sealant presented a significant shrinkage process, Control showed a slight swelling over time. In addition, E-sealant presented a high enzymatic resorption rate, while Control showed to withstand the biodegradation process in a significant way. E-sealant presents optimal biochemical and biomechanical properties suitable for its use as a fibrin sealant with regenerative purposes.

Favorable short-term outcomes of micronized allogenic cartilage scaffold for glenoid cartilage defects associated with posterior glenohumeral instability

Purpose

To determine clinical outcomes associated with micronized allogenic cartilage scaffold use for treatment of posterior glenoid cartilage defects at 2 years.

Study Design

Case series.

Methods

A retrospective analysis of prospectively collected data was performed on a consecutive series of patients who underwent arthroscopic treatment of a symptomatic posterior glenoid cartilage defect with micronized allogenic cartilage scaffold between January 2019 and December 2020. The primary outcome was subjective shoulder value (SSV) at latest follow-up. Secondary outcomes included visual analog scale (VAS), recurrence of instability, and range of motion (ROM).

Results

Seven patients, including 4 in the setting of primary posterior instability and 3 in the setting of recurrent symptoms after arthroscopic posterior glenohumeral stabilization, were included in the analysis with a mean follow up of 2.6 years (range, 2-3.7 years). Statistically significant improvements were seen in SSV (median = 40, interquartile range [IQR] = 40-50 before surgery; vs median = 85, IQR = 67.5-87.5 after surgery; P = .018) and VAS (median = 4, IQR = 4-6.3 before surgery; vs median = 1, IQR = 0-1.5 after surgery; P = .010). No significant differences were seen in ROM. There were no cases of recurrent instability or reoperation.

Conclusions

The use of micronized allogenic cartilage scaffold for glenoid cartilage defects is associated with clinical improvement at 2-year follow-up. This is the case when performed in conjunction with index posterior labral repair when there is a concomitant glenoid cartilage defect or when performed in the setting of persistent pain and mechanical symptoms after prior posterior labral repair.

Level of Evidence

Level IV, therapeutic case series.

Minced Cartilage Implantation in Acetabular Cartilage Defects: Case Series with 2-Year Results

OBJECTIVE

The objective was to evaluate clinical outcome and safety of arthroscopic, autologous minced cartilage implantation for acetabular cartilage lesions observed during hip arthroscopy to treat femoroacetabular impingement syndrome (FAIS).

DESIGN

Eleven male patients, average age: 29.4 ± 5.4 years, average body mass index (BMI): 24.2 ± 2.2 kg/m2, scheduled for hip arthroscopy due to FAIS accompanied by an acetabular cartilage lesion were included in the case series. Cartilage tissue was harvested and minced from the loose cartilage flap at the chondrolabral lesion by arthroscopic shaver, augmented with autologous conditioned plasma, implanted into the defect, and fixated by autologous thrombin. Concomitant interventions were performed as indicated. The patients were evaluated preoperatively and at 24-month follow-up, using the International Hip Outcome Tool-12 (iHOT-12) and Visual Analog Scale (VAS) pain score and by magnetic resonance imaging (MRI) using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) grading scale at the 2-year follow-up.

RESULTS

The defect size was on average 3.5 cm2 (1.5-4.5 cm2). From preoperatively to 2 years postoperatively, the iHOT-12 significantly improved from 50.2 ± 18 to 86.5 ± 19 (P < 0.0001), and pain score decreased from 5.6 ± 1.8 to 1.0 ± 1.5 (P < 0.0001) on the Visual Analog Scale pain score. Regarding functional outcome and pain, 10 of the 11 patients and all patients reached the minimal clinically important difference (MCID), respectively. The postoperative average MOCART score was 87.2 (± 9.2). No adverse events or reoperations were observed.

CONCLUSIONS

Arthroscopic, autologous minced cartilage implantation for treating full-thickness acetabular cartilage lesions in FAIS shows statistically and clinically significant improvement at short-term follow-up.

Biological and Adhesive Properties of an Autologous Protein-Based Fibrin Sealant for Ophthalmological Applications

Purpose

The aim of this study was to evaluate the biological and adhesive properties of a new autologous sealant based on plasma rich in growth factors (PRGF), named E-Sealant.

Methods

Conventional PRGF and a commercial fibrin sealant (Tisseel) were included as controls. The hematological and protein content of E-Sealant was determined. Its bioactivity and biocompatibility were tested for human keratocytes (HKs). To evaluate its adhesion and regenerative capacity, E-Sealant was used on an animal model of conjunctival autograft surgery and compared to Tisseel.

Results

E-Sealant presented a high growth factor content with levels similar to those of conventional PRGF. E-Sealant induced proliferative and migratory activity on HK cells equivalent to PRGF. Although autologous membranes induced the proliferation of HKs, cells cultured over Tisseel did not adhere nor proliferate. HK cells showed increased number and flattened morphology over PRGF and E-Sealant compared to scarce and round-shape cells detected in Tisseel. Conjunctival autograft glued with E-Sealant adhered successfully, whereas Tisseel application formed irregular clots. During follow-up, both adhesives showed good integration and no dehiscence. However, Tisseel-treated samples presented slightly increased hemorrhage and inflammation. In contrast to Tisseel, E-Sealant-treated autografts presented a continuous layer of non-keratinized stratified squamous epithelium. Inflammatory infiltrates were minimal in E-Sealant-treated conjunctiva, whereas the Tisseel group showed noticeable immune reactions. Unlike Tisseel-treated grafts, E-Sealant presented low immunoreactivity for smooth muscle actin (SMA), suggesting decreased fibrotic tissue formation.

Conclusions

E-Sealant presents optimal biological and adhesive properties suitable for use as an ophthalmic glue, with regenerative purposes superior to commercial fibrin sealants.

Translational Relevance

Our study analyzed the characterization and biological activity of a new autologous fibrin sealant in ocular surface cells and in an animal model in which the adhesive and regenerative properties of the fibrin sealant were evaluated.

[Minced cartilage procedure for the treatment of acetabular cartilage lesions of the hip joint]

OBJECTIVE

Treatment of acetabular cartilage defects using autologous cartilage fragments.

INDICATIONS

Acetabular cartilage damage (1-6 cm2) associated with femoroacetabular impingement syndrome (FAIS).

CONTRAINDICATIONS

Advanced osteoarthritis (≥ 2 according to Tönnis) and extensive acetabular cartilage damage > 6 cm2. Lack of labral containment due to irreparable labral damage.

SURGICAL TECHNIQUE

Arthroscopic preparation of the acetabular cartilage damage and removal of unstable cartilage fragments using a 4.0 mm shaver, which minces the cartilage fragments. If necessary, additional cartilage harvesting over the CAM morphology requiring resection. Collection of the cartilage fragments using GraftnetTM and augmentation with autologous conditioned plasma (ACP). Treatment of associated pathologies such as CAM morphology, pincer morphology, and labral refixation or reconstruction. Implantation of cartilage mass and remodeling into the defect zone. Final sealing with autologous fibrin.

POSTOPERATIVE MANAGEMENT

Postoperatively, weight bearing is restricted to 20 kg and range of motion to 90° of flexion for 6 weeks. This is supplemented by passive movement using a continuous passive motion (CPM) device.

RESULTS

Since 2021, 13 patients treated with the described method were followed up for at least 6 months. A significant increase in the International Hip Outcome Tool (iHot)-12 and a significant reduction of pain were observed. No severe complications occurred.

Biologic principles of minced cartilage implantation: a narrative review

Cartilage tissue has a very limited ability to regenerate. Symptomatic cartilage lesions are currently treated by various cartilage repair techniques. Multiple treatment techniques have been proposed in the last 30 years. Nevertheless, no single technique is accepted as a gold standard. Minced cartilage implantation is a newer technique that has garnered increasing attention. This procedure is attractive because it is autologous, can be performed in a single surgery, and is therefore given it is cost-effective. This narrative review provides an overview of the biological potential of current cartilage regenerative repair techniques with a focus on the translational evidence of minced cartilage implantation.

Fibrin deposition associates with cartilage degeneration in arthritis

Background

Cartilage damage in inflammatory arthritis is attributed to inflammatory cytokines and pannus infiltration. Activation of the coagulation system is a well known feature of arthritis, especially in rheumatoid arthritis (RA). Here we describe mechanisms by which fibrin directly mediates cartilage degeneration.

Methods

Fibrin deposits were stained on cartilage and synovial tissue of RA and osteoarthritis (OA) patients and in murine adjuvant-induced arthritis (AIA) in wild-type or fibrinogen deficient mice. Fibrinogen expression and procoagulant activity in chondrocytes were evaluated using qRT-PCR analysis and turbidimetry. Chondro-synovial adhesion was studied in co-cultures of human RA cartilage and synoviocytes, and in the AIA model. Calcific deposits were stained in human RA and OA cartilage and in vitro in fibrinogen-stimulated chondrocytes.

Findings

Fibrin deposits on cartilage correlated with the severity of cartilage damage in human RA explants and in AIA in wild-type mice, whilst fibrinogen deficient mice were protected. Fibrin upregulated Adamts5 and Mmp13 in chondrocytes. Chondro-synovial adhesion only occurred in fibrin-rich cartilage areas and correlated with cartilage damage. In vitro, autologous human synoviocytes, cultured on RA cartilage explants, adhered exclusively to fibrin-rich areas. Fibrin co-localized with calcification in human RA cartilage and triggered chondrocyte mineralization by inducing pro-calcification genes (Anx5, Pit1, Pc1) and the IL-6 cytokine. Similar fibrin-mediated mechanisms were observed in OA models, but to a lesser extent and without pseudo-membranes formation.

Interpretation

In arthritis, fibrin plaques directly impair cartilage integrity via a triad of catabolism, adhesion, and calcification.

Funding

None.

Autologous Fibrin Sealants Have Comparable Graft Fixation to an Allogeneic Sealant in a Biomechanical Cadaveric Model of Chondral Defect Repair

Purpose

The purpose of this study is to assess the integrity of chondral defect repairs filled with a cartilage allograft and sealed with either allogeneic fibrin sealant or autologous fibrin sealants created with platelet-rich plasma (PRP) or platelet-poor plasma (PPP) in a cadaver model.

Methods

Twenty-millimeter medial femoral condyle (MFC) chondral defects were created in five human cadaveric knees. The defects were filled with particulated cartilage allograft hydrated with PRP from human donors until slightly recessed. Sealants were applied until flush with the articular surface using PRP and autologous thrombin serum, PPP and autologous thrombin serum, or commercial allogeneic sealant. The MFC defects were cycled using a multiaxial testing system to simulate continuous passive motion undergone during rehabilitation. After testing, the repairs were assessed for integrity by quantitatively comparing defect exposure and qualitatively assessing sealant delamination.

Results

The mean defect exposures were 4.20% ± 5.02% for the PRP group, 4.60% ± 5.18% for the PPP group, and 1.80% ± 2.95% for the allogeneic sealant group. No significant differences were observed between groups (P = .227), and each group had significantly less defect exposure when compared to the critical clinically relevant value assigned to be 30% (P = <.001 for all). No complete sealant delamination was observed, although the allogeneic sealant delaminated with a higher magnitude than did the autologous sealants.

Conclusions

The PRP and PPP sealants were comparable to the allogeneic sealant for graft fixation when used in conjunction with an underlying PRP-hydrated particulated cartilage allograft. The autologous sealants had better delamination resistance than the allogeneic sealant.

Clinical Relevance

The time-zero model is critical in elucidating the retention properties of fibrin and allogenic sealants after cartilage repair and before healing processes help stabilize the repair.

Autologous Minced Cartilage Implantation for Treatment of Chondral and Osteochondral Lesions in the Knee Joint: An Overview

Cartilage defects in the knee are being diagnosed with increased frequency and are treated with a variety of techniques. The aim of any cartilage repair procedure is to generate the highest tissue quality, which might correlate with improved clinical outcomes, return-to-sport, and long-term durability. Minced cartilage implantation (MCI) is a relatively simple and cost-effective technique to transplant autologous cartilage fragments in a single-step procedure. Minced cartilage has a strong biologic potential since autologous, activated non-dedifferentiated chondrocytes are utilized. It can be used both for small and large cartilage lesions, as well as for osteochondral lesions. As it is purely an autologous and homologous approach, it lacks a significant regulatory oversight process and can be clinically adopted without such limitations. The aim of this narrative review is to provide an overview of the current evidence supporting autologous minced cartilage implantation.

Minced Cartilage Implantation for a Cystic Defect on the Femoral Head-Technical Note

Chondral injuries of the femoral head and their possible progression to osteoarthritis is well known. Regarding focal lesions in young patients, microfracturing or autologous chondrocyte implantation (ACI) are the most frequent used techniques to address them. Although ACI provides the better tissue quality, it is a two-step procedure and needs a lot of resources. Mincing cartilage is an old technique that has become popular again over the last few years, with good short-term results in threatening cartilage lesion in the knee. It seems intriguing to transfer this technique to the hip because you can harvest good-quality cartilage from the cam lesion, and it is a one-step procedure using autologous thrombin and fibrin. This technical note describes the repair of a parafoveal chondral defect using minced cartilage via surgical dislocation of the hip.

Treatment of a coronal shear injury of the trochlea using a modified hedgehog-based technique through an anterior neurovascular interval approach: A case report

INTRODUCTION AND IMPORTANCE

Surgical treatment for dislocated trochlear shear injuries is recommended due to its articular nature. However, the surgical exposure is often limited and large cartilaginous fragments with lack of subchondral bone stock makes a stable fixation technically challenging. Rapid swelling of the traumatized cartilage induces a size misfit between the cartilage of the fragment and the defect site. The use of a "modified hedgehog"-based technique might be a solution in these cases. However, this technique has only been described in chondral shear lesions of the knee.

CASE PRESENTATION

A fifteen-year-old boy fell out of the still rings during gymnastics at school and suffered trauma to his elbow. A CT-scan of the right elbow showed a coronal shear injury of the trochlea with accompanied lateral condyle fracture of the humerus. The patient was treated throughout an anterior neurovascular approach with a modified hedgehog-based technique with triple fixation by creating an interlocking match of the cartilage, application of fibrin glue and additional screw fixation.

CLINICAL DISCUSSION

The anterior neurovascular interval approach provides a clear exposure of the fracture site which is useful for anatomic reduction and triple fixation. The subsequent modified hedgehog-based technique has only been described once in children with shear-off chondral fragments of the knee, without additional screw fixation. Adding a screw fixation of the fragment creates some collateral damage to the cartilage and might not be necessary in future cases.

CONCLUSION

The anterior neurovascular approach seems elegant and provides adequate exposure. Furthermore, a modified hedgehog-based technique delivers a stable triple fixation of the osteochondral fragment.

Porcine fibrin sealant combined with autologous chondrocytes successfully promotes full-thickness cartilage regeneration in a rabbit model

Xenogeneic porcine fibrin sealant (PFS), derived from porcine blood, was used as a scaffold for cartilage tissue engineering. PFS has a porous microstructure, biocompatibility and degradation, and it provides a perfect extracellular matrix environment for the adhesion and proliferation of chondrocytes. Recently, PFS in combination with autologous chondrocytes (ACs) were used to study the microstructure of PFS scaffolds and promotion effect on the proliferation and migration of ACs. In this study, we investigated the effects of PFS in combination with ACs on the healing of cartilage defects in rabbits. A full‐thickness cartilage defect was made in the femoral trochlear in rabbits, subsequently, three surgical procedures were used to repair the defect, namely: the defect was treated with microfracture (MF group); the defect was filled with PFS alone (PFS group) or in combination with ACs (PFS + ACs group); the unrepaired cartilage defects served as the control group (CD group). Three and 6 months after the operation, the reparative effect was evaluated using medical imaging, gross scoring, pathological staining, biomechanical testing and biochemical examination. The PFS group showed a limited effect on defect repair, this result was significantly worse than the MF group. The best reparative effect was observed in the PFS + ACs group. These results hinted that PFS in combination with autologous chondrocytes has broad prospects for clinical applications in cartilage tissue engineering.

Arthroscopic Minced Cartilage Implantation for Chondral Lesions at the Talus: A Technical Note

In the past few years, autologous chondrocyte implantation has been shown to be the most suitable cartilage reconstructive technique with the best tissue quality. Although this method is part of the standard surgical repertoire in the knee joint, it has so far not been an established method in the ankle because there are no prospective randomized controlled studies to prove a significant advantage over alternative methods of cartilage repair. The methods most frequently used in this context (e.g., marrow stimulation techniques) can, however, at most generate hyaline-like and thus biomechanically inferior regenerates. Minced cartilage implantation, on the other hand, is a relatively simple and cost-effective 1-step procedure with promising biological potential and-at least in the knee joint-satisfactory clinical results. We present an arthroscopic surgical technique by which the surgeon can apply autologous chondrocytes in a 1-step procedure (AutoCart; Arthrex, Munich, Germany) to treat articular cartilage defects in the ankle joint.

Assisted therapy with platelet-rich plasma for burn patients: A meta-analysis and systematic review

INTRODUCTION

Platelet-rich plasma (PRP) therapy has been used in different medical fields, but its effectiveness in burn wound healing remains debatable. In this study, we performed a systematic review and meta-analysis of the available evidence on burn patients treated with PRP to evaluate the safety and efficacy of the treatment.

METHODS

Randomized controlled trials evaluating the efficacy of PRP in patients with burn injuries were selected. Eligible retrospective studies were abstracted and assessed for the risk of bias by two reviewers and results of mean time to complete epithelization and wound closure rate in the included studies were analyzed. Studies on the correlation between PRP and burn wound healing published in English or Chinese before March 2020 were retrieved from PubMed.

RESULTS

Eight studies (including 449 patients) met our inclusion criteria. Qualitative analysis revealed that compared with the control group, the PRP group had significantly better wound closure rates at weeks 2 (mean difference (MD): 12.79 [95% confidence interval (CI): 7.08, 18.49]; I2: 0%; p < 0.0001) and 3 (MD: 12.66 [95% CI: 5.97, 19.34]; I2: 55%; p = 0.0002) and time to complete epithelialization (MD: -3.45 [95% CI: -4.87, -2.04] (days); I2: 0%; p < 0.00001). There was no significant difference in infection rate or graft take rate.

CONCLUSIONS

PRP application can accelerate wound closure, however, it has no effect on the rates of wound infection and graft take rate.

Arthroscopic Minced Cartilage Implantation (MCI): A Technical Note

Articular cartilage lesions are identified with increasing frequency. Several cartilage repair techniques are available to treat symptomatic cartilage defects. The ultimate goal of any cartilage repair procedure is the prevention of premature osteoarthritis. Autologous chondrocyte implantation provides the best tissue quality. However, 2 operations and a resource-intense culturing process with high regulatory demands are disadvantages of this cartilage repair procedure. Furthermore, cellular dedifferentiation and senescence display further cell culture-associated drawbacks that hamper the procedure. Minced cartilage implantation is a relatively simple and cost-effective one-step procedure with promising biologic potential and satisfying clinical results. We present an arthroscopic surgical technique where the surgeon can apply autologous chondrocytes in a one-step procedure to treat articular cartilage defects at the knee joint.

Microscale strain mapping demonstrates the importance of interface slope in the mechanics of cartilage repair

Achieving lateral integration of articular cartilage repair tissue with surrounding native cartilage remains a clinical challenge. Histological and bulk mechanical studies have identified extracellular matrix components that correlate with superior failure strength, but it is unclear how local changes in geometry and composition at the repair interface affect tissue strains under physiologic loading. Here, we investigated the effects of local compositional and interface geometry on lateral cartilage repair integration by coupling microscale Raman spectroscopy and confocal elastography to measure tissue strains under compressive and shear loading. Histological integration assessments did not have significant relationships with interface strains under compressive loading (p > 0.083) and only the perimeter attachment score was trending towards statistical significance with the |E_xy| strain tensor under shear loading (p = 0.050). Interface slope had a stronger correlation with local tissue strains under compressive and shear loading compared to compositional measures of GAG, collagen, or proteins (compressive loading |E_yy| tensor: R² = 0.400 (interface slope), 0.005 (GAG), 0.024 (collagen), and 0.012 (protein); shear loading |E_xy| tensor: R² = 0.457 (interface slope), 0.003 (GAG), 0.006 (collagen), and 0.000 (total protein)). These data support surgical publications detailing the need for vertical walls when debriding chondral defects. Current histological integration assessments and local compositional measures were insufficient for identifying the variation in interface strains under compressive and shear loading. Thus, our data points to the importance of controlling interface geometry at the time of surgery, which has implications for cartilage repair integration and long-term healing.

Platelet-Derived Products in Veterinary Medicine: A New Trend or an Effective Therapy?

Platelet-derived products (PDPs) have gained popularity, mainly due to their high concentrations of bioactive molecules such as growth factors and cytokines, which play important roles in tissue healing and regeneration. PDPs are obtained through minimally invasive procedures and their therapeutic effect has been widely recognized. In veterinary medicine, however, the lack of standard protocols to generate PDPs is a major hurdle for assessing the clinical relevance of PDP-based therapies and for their widespread usage. The aim of this review is to analyze the technical and scientific specificities of PDPs in terms of preparation methodologies, classification categorization, nomenclature, and biological proprieties to advance their future biotechnological potential in veterinary contexts.

Current State of Bone Adhesives-Necessities and Hurdles

The vision of gluing two bone fragments with biodegradable and biocompatible adhesives remains highly fascinating and attractive to orthopedic surgeons. Possibly shorter operation times, better stabilization, lower infection rates, and unnecessary removal make this approach very appealing. After 30 years of research in this field, the first adhesive systems are now appearing in scientific reports that may fulfill the comprehensive requirements of bioadhesives for bone. For a successful introduction into clinical application, special requirements of the musculoskeletal system, challenges in the production of a bone adhesive, as well as regulatory hurdles still need to be overcome. In this article, we will give an overview of existing synthetic polymers, biomimetic, and bio-based adhesive approaches, review the regulatory hurdles they face, and discuss perspectives of how bone adhesives could be efficiently introduced into clinical application, including legal regulations.