Repair of orbital bone defects in canines using grafts of enriched autologous bone marrow stromal cells

Biopolymeric Innovations in Ophthalmic Surgery: Enhancing Devices and Drug Delivery Systems

The interface between material science and ophthalmic medicine is witnessing significant advances with the introduction of biopolymers in medical device fabrication. This review discusses the impact of biopolymers on the development of ophthalmic devices, such as intraocular lenses, stents, and various prosthetics. Biopolymers are emerging as superior alternatives due to their biocompatibility, mechanical robustness, and biodegradability, presenting an advance over traditional materials with respect to patient comfort and environmental considerations. We explore the spectrum of biopolymers used in ophthalmic devices and evaluate their physical properties, compatibility with biological tissues, and clinical performances. Specific applications in oculoplastic and orbital surgeries, hydrogel applications in ocular therapeutics, and polymeric drug delivery systems for a range of ophthalmic conditions were reviewed. We also anticipate future directions and identify challenges in the field, advocating for a collaborative approach between material science and ophthalmic practice to foster innovative, patient-focused treatments. This synthesis aims to reinforce the potential of biopolymers to improve ophthalmic device technology and enhance clinical outcomes.

The Use of Functional Biomaterials in Aesthetic and Functional Restoration in Orbital Surgery

The integration of functional biomaterials in oculoplastic and orbital surgery is a pivotal area where material science and clinical practice converge. This review, encompassing primary research from 2015 to 2023, delves into the use of biomaterials in two key areas: the reconstruction of orbital floor fractures and the development of implants and prostheses for anophthalmic sockets post-eye removal. The discussion begins with an analysis of orbital floor injuries, including their pathophysiology and treatment modalities. It is noted that titanium mesh remains the gold standard for orbital floor repair due to its effectiveness. The review then examines the array of materials used for orbital implants and prostheses, highlighting the dependence on surgeon preference and experience, as there are currently no definitive guidelines. While recent innovations in biomaterials show promise, the review underscores the need for more clinical data before these new materials can be widely adopted in clinical settings. The review advocates for an interdisciplinary approach in orbital surgery, emphasizing patient-centered care and the potential of biomaterials to significantly enhance patient outcomes.

Comparative characteristic study from bone marrow-derived mesenchymal stem cells

Tissue engineering has been extensively investigated and proffered to be a potential platform for novel tissue regeneration. The utilization of mesenchymal stem cells (MSCs) from various sources has been widely explored and compared. In this regard, MSCs derived from bone marrow have been proposed and described as a promising cell resource due to their high yield of isolated cells with colony-forming potential, self-renewal capacity, MSC surface marker expression, and multi-lineage differentiation capacities in vitro. However, there is evidence for bone marrow MSCs (BM-MSCs) both in vitro and in vivo from different species presenting identical and distinct potential stemness characteristics. In this review, the fundamental knowledge of the growth kinetics and stemness properties of BM-MSCs in different animal species and humans are compared and summarized. Finally, to provide a full perspective, this review will procure results of current information studies focusing on the use of BM-MSCs in clinical practice.

Challenges of stem cell therapies in companion animal practice

Regenerative medicine using stem cells from various sources are emerging treatment modality in several refractory diseases in veterinary medicine. It is well-known that stem cells can differentiate into specific cell types, self-renew, and regenerate. In addition, the unique immunomodulatory effects of stem cells have made stem cell transplantation a promising option for treating a wide range of disease and injuries. Recently, the medical demands for companion animals have been rapidly increasing, and certain disease conditions require alternative treatment options. In this review, we focused on stem cell application research in companion animals including experimental models, case reports and clinical trials in dogs and cats. The clinical studies and therapeutic protocols were categorized, evaluated and summarized according to the organ systems involved. The results indicate that evidence for the effectiveness of cell-based treatment in specific diseases or organ systems is not yet conclusive. Nonetheless, stem cell therapy may be a realistic treatment option in the near future, therefore, considerable efforts are needed to find optimized cell sources, cell numbers and delivery methods in order to standardize treatment methods and evaluation processes.

Mesenchymal stem cell-based bone tissue engineering for veterinary practice

Bone tissue engineering has been widely studied and proposed as a promising platform for correcting the bone defects. The applications of mesenchymal stem cell (MSC)-based bone tissue engineering have been investigated in various in vitro and in vivo models. In this regard, the promising animal bone defect models have been employed for illustrating the bone regenerative capacity of MSC-based bone tissue engineering. However, most studies aimed for clinical applications in human. These evidences suggest a knowledge gap to fulfill the accomplishment for veterinary implementation. In this review, the fundamental concept, knowledge, and technology of MSC-based bone tissue engineering focusing on veterinary applications are summarized. In addition, the potential canine MSCs resources for veterinary bone tissue engineering are reviewed, including canine bone marrow-derived MSCs, canine adipose-derived MSCs, and canine dental tissue-derived MSCs. This review will provide a basic and current information for studies aiming for the utilization of MSC-based bone tissue engineering in veterinary practice.

Intraoperative Construct Preparation: A Practical Route for Cell-Based Bone Regeneration

Stem cell-based bone tissue engineering based on the combination of a scaffold and expanded autologous mesenchymal stem cells (MSCs) represents the current state-of-the-art treatment for bone defects and fractures. However, the procedure of such construct preparation requires extensive ex vivo manipulation of patient's cells to achieve enough stem cells. Therefore, it is impractical and not cost-effective compared to other therapeutic interventions. For these reasons, a more practical strategy circumventing any ex vivo manipulation and an additional surgery for the patient would be advantageous. Intraoperative concept-based bone tissue engineering, where constructs are prepared with easily accessible autologous cells within the same surgical procedure, allows for such a simplification. In this study, we discuss the concept of intraoperative construct preparation for bone tissue engineering and summarize the available cellular options for intraoperative preparation. Furthermore, we propose methods to prepare intraoperative constructs, and review data of currently available preclinical and clinical studies using intraoperatively prepared constructs for bone regenerative applications. We identify several obstacles hampering the application of this emerging approach and highlight perspectives of technological innovations to advance the future developments of intraoperative construct preparation.

Long-term Radiological and Clinical Outcomes After Using Bone Marrow Mesenchymal Stem Cells Concentrate Obtained With Selective Retention Cell Technology in Posterolateral Spinal Fusion

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim of this study was to evaluate the long-term clinical and radiological outcomes of the use of bone marrow mesenchymal stem cell concentrate obtained with selective cell retention technology using Cellect with a particular collagen scaffold, Healos for posterolateral spinal fusion.

SUMMARY OF BACKGROUND DATA

With the increasing rate of spinal fusion, the problem of pseudarthrosis, which contributes to recurrent pain with patient disability, is considered to be the most common cause of revision lumbar spine surgery. Intensive research is being carried out to develop an alternative source of bone grafting and improve the spinal fusion rate.

METHODS

A retrospective review of hospital records was performed. Identified patients were contacted to have a clinical and radiological evaluation follow-up. Clinical outcome was evaluated using visual analog scales for the back pain (VAS), Oswestry Disability Index (ODI) scores, and quality of life (EQ-5D) questionnaire. Radiological outcome was evaluated by performing dynamic flexion/extension lateral views and calculation of segmental Cobb angle. Any implant-associated complication was reported. Computed tomography (CT) scans were also performed.

RESULTS

Twenty-one patients were included and all patients achieved successful fusion. The mean difference of the segmental Cobb angle was 0.48° (range 0.3°-0.7°). Computed tomography scans showed solid bilateral fusion with bridging bone (Grade I) in all patients, but solid unilateral fusion with bridging bone (Grade II) was detected for one patient at one level. Patients started to resume working activities within a mean period of 3.5 months. The VAS score for the residual back pain was 4.1 ± 2.1, whereas the ODI was 10.5 ± 5.6 points, and the mean disability index was 21.1%.

CONCLUSION

The use of bone marrow mesenchymal stem cell concentrate obtained with selective cell retention technology could be considered as an effective means for augmenting spinal fusion.

LEVEL OF EVIDENCE

3.

Bone Regeneration Induced by Bone Porcine Block with Bone Marrow Stromal Stem Cells in a Minipig Model of Mandibular "Critical Size" Defect

Introduction. Adding stem cells to biodegradable scaffolds to enhance bone regeneration is a valuable option. Different kinds of stem cells with osteoblastic activity were tested, such as bone marrow stromal stem cells (BMSSCs). Aim. To assess a correct protocol for osteogenic stem cell differentiation, so BMSSCs were seeded on a bone porcine block (BPB). Materials and Methods. Bone marrow from six minipigs was extracted from tibiae and humeri and treated to isolate BMSSCs. After seeding on BPB, critical-size defects were created on each mandible of the minipigs and implanted with BPB and BPB/BMSSCs. After three months, histomorphometric analysis was performed. Results. Histomorphometric analysis provided percentages of the three groups. Tissues present in control defects were 23 ± 2% lamellar bone, 28 ± 1% woven bone, and 56 ± 4% marrow spaces; in BPB defects were 20 ± 5% BPB, 32 ± 2% lamellar bone, 24 ± 1% woven bone, and 28 ± 2% marrow spaces; in BPB/BMSSCs defects were 17 ± 4% BPB/BMSSCs, 42 ± 2% lamellar bone, 12 ± 1% woven bone, and 22 ± 3% marrow spaces. Conclusion. BPB used as a scaffold to induce bone regeneration may benefit from the addition of BDPSCs in the tissue-engineered constructs.

Overcoming translational challenges - The delivery of mechanical stimuli in vivo

Despite major medical advances, non-union bone fractures and skeletal defects continue to place significant burden on the patient, the clinicians and the healthcare system as a whole. Current bone substitute approaches are still limited in effectiveness and to date no adequate bone substitute material has been developed for routine clinical application. Tissue engineering presents a novel approach to tackling this clinical burden and developing an acceptable solution for the treatment of skeletal defects. Over the past three decades the field has evolved to appreciate the key biological, material and physical parameters influencing the development of a cell-based tissue engineered therapy and to create associated technologies to exploit such parameters. In recent years a number of therapies have started progressing along the pre-clinical pipeline to build a case for regulatory approval and ultimately clinical adoption. However, little emphasis has been given to the translational challenges faced when moving from "bench-to-bedside". One particular challenge lies in the delivery of functional mechanical stimuli to implanted cell populations to activate and promote osteogenic activities. This review introduces novel bio-magnetic approaches to overcoming this challenge.