- Mesenchymal stem cells-seeded bio-ceramic construct for bone regeneration in large critical-size bone defect in rabbit. [Journal Article]
- JSJ Stem Cells Regen Med 2016; 12(2):87-99
- Bone marrow derived mesenchymal stem cells (BMSC) represent an attractive cell population for tissue engineering purpose. The objective of this study was to determine whether the addition of recombin...
Bone marrow derived mesenchymal stem cells (BMSC) represent an attractive cell population for tissue engineering purpose. The objective of this study was to determine whether the addition of recombinant human bone morphogenetic protein (rhBMP-2) and insulin-like growth factor (IGF-1) to a silica-coated calcium hydroxyapatite (HASi) - rabbit bone marrow derived mesenchymal stem cell (rBMSC) construct promoted bone healing in a large segmental bone defect beyond standard critical -size radial defects (15mm) in rabbits. An extensively large 30mm long radial ostectomy was performed unilaterally in thirty rabbits divided equally in five groups. Defects were filled with a HASi scaffold only (group B); HASi scaffold seeded with rBMSC (group C); HASi scaffold seeded with rBMSC along with rhBMP-2 and IGF-1 in groups D and E respectively. The same number of rBMSC (five million cells) and concentration of growth factors rhBMP-2 (50µg) and IGF-1 (50µg) was again injected at the site of bone defect after 15 days of surgery in their respective groups. An empty defect served as the control group (group A). Radiographically, bone healing was evaluated at 7, 15, 30, 45, 60 and 90 days post implantation. Histological qualitative analysis with microCT (µ-CT), haematoxylin and eosin (H & E) and Masson's trichrome staining were performed 90 days after implantation. All rhBMP-2-added constructs induced the formation of well-differentiated mineralized woven bone surrounding the HASi scaffolds and bridging bone/implant interfaces as early as eight weeks after surgery. Bone regeneration appeared to develop earlier with the rhBMP-2 constructs than with the IGF-1 added construct. Constructs without any rhBMP-2 or IGF-1 showed osteoconductive properties limited to the bone junctions without bone ingrowths within the implantation site. In conclusion, the addition of rhBMP-2 to a HASi scaffold could promote bone generation in a large critical-size-defect.
- A central giant cell granuloma in posterior part of maxilla-A case report. [Journal Article]
- IJInt J Surg Case Rep 2016 Nov 17
- CONCLUSIONS: Giant Cell Granuloma is a rare bony lesion in the Head and Neck region. It is a non-odontogenic tumor never seen in any other bone of the skeleton. It most commonly affects maxilla followed by the mandible.There is no recurrence after a long follow up period. We concluded that conventional excision is to be considered as a best method to treat central giant cell granuloma.
- Scale-up of nature's tissue weaving algorithms to engineer advanced functional materials. [Journal Article]
- SRSci Rep 2017 Jan 11; 7:40396
- We are literally the stuff from which our tissue fabrics and their fibers are woven and spun. The arrangement of collagen, elastin and other structural proteins in space and time embodies our tissues...
We are literally the stuff from which our tissue fabrics and their fibers are woven and spun. The arrangement of collagen, elastin and other structural proteins in space and time embodies our tissues and organs with amazing resilience and multifunctional smart properties. For example, the periosteum, a soft tissue sleeve that envelops all nonarticular bony surfaces of the body, comprises an inherently "smart" material that gives hard bones added strength under high impact loads. Yet a paucity of scalable bottom-up approaches stymies the harnessing of smart tissues' biological, mechanical and organizational detail to create advanced functional materials. Here, a novel approach is established to scale up the multidimensional fiber patterns of natural soft tissue weaves for rapid prototyping of advanced functional materials. First second harmonic generation and two-photon excitation microscopy is used to map the microscopic three-dimensional (3D) alignment, composition and distribution of the collagen and elastin fibers of periosteum, the soft tissue sheath bounding all nonarticular bone surfaces in our bodies. Then, using engineering rendering software to scale up this natural tissue fabric, as well as multidimensional weaving algorithms, macroscopic tissue prototypes are created using a computer-controlled jacquard loom. The capacity to prototype scaled up architectures of natural fabrics provides a new avenue to create advanced functional materials.
- Braided and Stacked Electrospun Nanofibrous Scaffolds for Tendon and Ligament Tissue Engineering. [Journal Article]
- TETissue Eng Part A 2017 Jan 10
- Tendon and ligament injuries are a persistent orthopaedic challenge given their poor innate healing capacity. Non-woven electrospun nanofibrous scaffolds composed of polyesters have been used to mimi...
Tendon and ligament injuries are a persistent orthopaedic challenge given their poor innate healing capacity. Non-woven electrospun nanofibrous scaffolds composed of polyesters have been used to mimic the mechanics and topographical cues of native tendons and ligaments. However, non-woven nanofibers have several limitations that prevent broader clinical application, including poor cell infiltration as well as tensile and suture-retention strengths that are inferior to native tissues. In this study, multilayered scaffolds of aligned electrospun nanofibers of two designs - stacked or braided - were fabricated. Mechanical properties, including structural and mechanical properties and suture-retention strength, were determined using acellular scaffolds. Human bone marrow-derived mesenchymal stem cells (MSCs) were seeded on scaffolds for up to 28 days and assays for tenogenic differentiation, histology, and biochemical composition were performed. Braided scaffolds exhibited improved tensile and suture retention strengths, but reduced moduli. Both scaffold designs supported expression of tenogenic markers, although the effect was greater on braided scaffolds. Conversely, cell infiltration was superior in stacked constructs, resulting in enhanced cell number, total collagen content, and total sulfated glycosaminoglycan (sGAG) content. However, when normalized against cell number, both designs modulated extracellular matrix (ECM) protein deposition to a similar degree. Taken together, this study demonstrates that multilayered scaffolds of aligned electrospun nanofibers supported tenogenic differentiation of seeded MSCs, but the macro-architecture is an important consideration for applications of tendon and ligament tissue engineering.
- Osseointegration of titanium, titanium alloy and zirconia dental implants: current knowledge and open questions. [Review]
- P2Periodontol 2000 2017; 73(1):22-40
- Bone healing around dental implants follows the pattern and sequence of intramembraneous osteogenesis with formation of woven bone first of all followed later by formation of parallel-fibered and lam...
Bone healing around dental implants follows the pattern and sequence of intramembraneous osteogenesis with formation of woven bone first of all followed later by formation of parallel-fibered and lamellar bone. Bone apposition onto the implant surface starts earlier in trabecular bone than in compact bone. While the first new bone may be found on the implant surface around 1 week after installation, bone remodeling starts at between 6 and 12 weeks and continues throughout life. Bone remodeling also involves the bone-implant interface, thus transiently exposing portions of the implant surface. Surface modifications creating micro-rough implant surfaces accelerate the osseointegration process of titanium implants, as demonstrated in numerous animal experiments. Sandblasting followed by acid-etching may currently be regarded as the gold standard technique to create micro-rough surfaces. Chemical surface modifications, resulting in higher hydrophilicity, further increase the speed of osseointegration of titanium and titanium-zirconium implants in both animals and humans. Surface modifications of zirconia and alumina-toughened zirconia implants also have an influence on the speed of osseointegration, and some implant types reach high bone-to-implant contact values in animals. Although often discussed independently of each other, surface characteristics, such as topography and chemistry, are virtually inseparable. Contemporary, well-documented implant systems with micro-rough implant surfaces, placed by properly trained and experienced clinicians, demonstrate high long-term survival rates. Nevertheless, implant failures do occur. A low percentage of implants are diagnosed with peri-implantitis after 10 years in function. In addition, a low number of implants seem to be lost for primarily reasons other than biofilm-induced infection. Patient factors, such as medications interfering with the immune system and bone cells, may be an element contributing to continuous bone loss and should therefore be monitored and studied in greater detail.
- Phase I/II Trial of Autologous Bone Marrow Stem Cell Transplantation with a Three-Dimensional Woven-Fabric Scaffold for Periodontitis. [Journal Article]
- SCStem Cells Int 2016; 2016:6205910
- Regenerative medicine is emerging as a promising option, but the potential of autologous stem cells has not been investigated well in clinical settings of periodontal treatment. In this clinical stud...
Regenerative medicine is emerging as a promising option, but the potential of autologous stem cells has not been investigated well in clinical settings of periodontal treatment. In this clinical study, we evaluated the safety and efficacy of a new regenerative therapy based on the surgical implantation of autologous mesenchymal stem cells (MSCs) with a biodegradable three-dimensional (3D) woven-fabric composite scaffold and platelet-rich plasma (PRP). Ten patients with periodontitis, who required a surgical procedure for intrabony defects, were enrolled in phase I/II trial. Once MSCs were implanted in each periodontal intrabony defect, the patients were monitored during 36 months for a medical exam including laboratory tests of blood and urine samples, changes in clinical attachment level, pocket depth, and linear bone growth (LBG). All three parameters improved significantly during the entire follow-up period (p < 0.0001), leading to an average LBG of 4.7 mm after 36 months. Clinical mobility measured by Periotest showed a decreasing trend after the surgery. No clinical safety problems attributable to the investigational MSCs were identified. This clinical trial suggests that the stem cell therapy using MSCs-PRP/3D woven-fabric composite scaffold may constitute a novel safe and effective regenerative treatment option for periodontitis.
- Exposure to Secondhand Smoke Impairs Fracture Healing in Rats. [Journal Article]
- COClin Orthop Relat Res 2016 Nov 30
- CONCLUSIONS: Rats exposed to tobacco smoke showed delayed fracture healing and callus that was characterized by decreased maturity, density, and mechanical resistance, which was confirmed by all assessment methods of this study. Such effects were more evident when animals were exposed to tobacco smoke before and after the fracture. Future studies should be done in human passive smokers to confirm or refute our findings on fracture callus formation.The potential hazardous effects of secondhand smoke on fracture healing in rodents should stimulate future clinical studies in human passive smokers.
- Effects of collagen membrane application and cortical bone perforation on de novo bone formation in periosteal distraction: an experimental study in a rabbit calvaria. [Journal Article]
- OSOral Surg Oral Med Oral Pathol Oral Radiol 2017; 123(2):173-182
- CONCLUSIONS: In the present model, cortical bone perforations have more impact on the osteogenic process compared with the application of a collagen membrane.
- Local Application of Lactoferrin Promotes Bone Regeneration In a Rat Critical-Sized Calvarial Defect Model As Demonstrated by Micro-CT And Histological Analysis. [Journal Article]
- JTJ Tissue Eng Regen Med 2016 Nov 15
- Lactoferrin is a multifunctional glycoprotein with therapeutic potential for bone tissue engineering. The aim of this study was to assess the efficacy of local application of lactoferrin on bone rege...
Lactoferrin is a multifunctional glycoprotein with therapeutic potential for bone tissue engineering. The aim of this study was to assess the efficacy of local application of lactoferrin on bone regeneration. Five-millimetre critical-sized defects were created over the right parietal bone in 64 Sprague-Dawley rats. The rats were randomized into four groups: group 1 (n = 20) had empty defects; group 2 (n = 20) had defects grafted with collagen gels (3 mg/mL); group 3 (n = 20) had defects grafted with collagen gels impregnated with bovine lactoferrin (10 µg/gel) and group 4 (n = 4) had sham surgeries (skin and periosteal incisions only). The rats were euthanized at 4 or 12 weeks post-operatively and the calvaria were excised and evaluated with micro-CT (Skyscan 1172) followed by histology. The bone volume fraction (BV/TV) was higher in lactoferrin treated animals at both time points, with groups 1, 2, 3 and 4 measuring 10.5 ± 1.1%, 8.6 ± 1.4%, 16.5 ± 0.6% and 24.27 ± 2.6%, respectively, at 4 weeks (p < 0.05); and 12.2 ± 1.3%, 13.6 ± 1.5%, 21.9 ± 1.2% and 29.3 ± 0.8%, respectively, at 12 weeks (p < 0.05). Histological analysis revealed that the newly formed bone within the calvarial defects of all groups was a mixture of woven and lamellar bone, with more bone in the group treated with lactoferrin at both timepoints. Our study demonstrated that local application of lactoferrin significantly increased bone regeneration in a rat critical-sized calvarial defect model. The profound effect of lactoferrin on bone regeneration has therapeutic potential to improve the poor clinical outcomes associated with bony non-union.
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- Remnant Woven Bone and Calcified Cartilage in Mouse Bone: Differences between Ages/Sex and Effects on Bone Strength. [Journal Article]
- PlosPLoS One 2016; 11(11):e0166476
- Mouse models are used frequently to study effects of bone diseases and genetic determinates of bone strength. Murine bones have an intracortical band of woven bone that is not present in human bones....
Mouse models are used frequently to study effects of bone diseases and genetic determinates of bone strength. Murine bones have an intracortical band of woven bone that is not present in human bones. This band is not obvious under brightfield imaging and not typically analyzed. Due to the band's morphology and location it has been theorized to be remnant bone from early in life. Furthermore, lamellar and woven bone are well known to have differing mechanical strengths. The purpose of this study was to determine (i) if the band is from early life and (ii) if the woven bone or calcified cartilage contained within the band affect whole bone strength.