Osteogenic potential of cultured human periosteum-derived cells – A pilot study of human cell transplantation into a rat calvarial defect model

Potential of periosteal cells in bone and cartilage regeneration: a systematic review

Introduction: The unavailability of adequate human primary cells presents multiple challenges in terms of bone and cartilage regeneration and disease modeling experiments in vitro. Periosteal cells (PCs), which represent promising skeletal stem cell sources, could be a promising strategy in tissue engineering. The present study aimed to summarize the characteristics of PCs to investigate the efficacy of these cells in bone and cartilage regeneration in different models, paying special attention to the comparison of bone marrow stromal cells (BMSCs). Methods: A comprehensive literature search was conducted in Embase, PubMed/MEDLINE, Web of Science, and Scopus for articles published in English until April 2023. Only original researches in which PCs were employed for bone or cartilage regeneration experiments were included. Results: A total of 9140 references were retrieved. After screening the results, 36 publications were considered to be eligible for inclusion in the present literature review. Overall, PCs demonstrated beneficial bone and cartilage regenerative efficacy compared to the bare scaffold since almost all included studies reported positive results. The 9 studies assessing the differences in bone formation capacity between PCs and BMSCs indicated that PCs exhibited stronger in vivo osteogenic differentiation capabilities compared to BMSCs, while the other study demonstrated stronger chondrogenic potential of BMSCs. Discussion: PCs demonstrated beneficial to bone regenerative efficacy compared to the bare scaffold with a low risk of most studies included. However, the cartilage formation capacity of BMSCs still needs to be investigated due to the limited research available and the certain risk of bias. PCs exhibited higher osteogenic capabilities compared to BMSCs in combination with various scaffolds in vivo with good evidence. Further researches are needed to elucidate the comparative benefits of cartilage regeneration. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023411522, CRD42023411522.

Jaw Periosteal Cells Seeded in Beta-Tricalcium Phosphate Inhibit Dendritic Cell Maturation

Mesenchymal stem cells (MSCs) have gained attraction not only in the field of regenerative medicine but also in the field of autoimmune disease therapies or organ transplantation due to their immunoregulatory and/or immunosuppressive features. Dendritic cells (DCs) play a crucial role in initiating and regulating immune reactions by promoting antigen-specific T cell activation. In this study, we investigated the effect of human jaw periosteal progenitor cells (JPCs) seeded in beta-tricalcium phosphate (β-TCP) scaffolds on monocyte-derived DC differentiation. Significantly lower numbers of differentiated DCs were observed in the presence of normal (Co) and osteogenically induced (Ob) JPCs-seeded β-TCP constructs. Gene expression analysis revealed significantly lower interleukin-12 subunit p35 (IL-12p35) and interleukin-12 receptor beta 2 (IL-12Rβ2) and pro-inflammatory cytokine interferon-gamma (IFN-γ) levels in DCs under Ob conditions, while interleukin-8 (IL-8) gene levels were significantly increased. Furthermore, in the presence of JPCs-seeded β-TCP constructs, interleukin-10 (IL-10) gene expression was significantly induced in DCs, particularly under Ob conditions. Analysis of DC protein levels shows that granulocyte-colony stimulating factor (G-CSF) was significantly upregulated in coculture groups. Our results indicate that undifferentiated and osteogenically induced JPCs-seeded β-TCP constructs have an overall inhibitory effect on monocyte-derived DC maturation.

Comparative Behavioral Assessment of Lewis and Nude Rats after Peripheral Nerve Injury

Cell therapy has shown potential in the field of peripheral nerve repair, and research using rodents is a critical and essential step toward clinical development of this approach. Traditionally, most experimental peripheral nerve injuries are conducted in inbred Lewis or outbred Sprague-Dawley strains. However, transplantation of xenogeneic cells such as human-derived cells typically triggers rejection in these animals. An alternative approach is to use immunodeficient animals, such as athymic nude rats. The lack of functional T cells in these animals renders them more accommodating to foreign cells from a different host. Currently, no literature exists regarding sensorimotor behavioral assessment of nude rats after peripheral nerve injury. To this end, we compared the functional recovery during a 6-wk period of behavioral testing of Lewis and nude rats after unilateral sciatic nerve crushing injury. Three sensorimotor behavioral assessments were performed weekly: a ladder rungwalking task to assess slip ratio and cross duration, von Frey nociception testing to determine the paw withdrawal threshold thus monitoring the regaining of sensory function, and sciatic functional index evaluation to monitor the recovery of integrated motor function. Both strains demonstrated significant sensory and motor deficits in the first week after injury, with a slight regain of sensory function, reduced slip ratio, and increased sciatic functional index starting at 2 wk. No significance difference existed between nude and Lewis rats in their recovery courses. We conclude that nude rats are a suitable model for behavioral training and assessment for cell transplantation studies in peripheral nerve injury and repair.

Reconstructing Bone with Natural Bone Graft: A Review of In Vivo Studies in Bone Defect Animal Model

Bone defects caused by fracture, disease or congenital defect remains a medically important problem to be solved. Bone tissue engineering (BTE) is a promising approach by providing scaffolds to guide and support the treatment of bone defects. However, the autologous bone graft has many defects such as limited sources and long surgical procedures. Therefore, xenograft bone graft is considered as one of the best substitutions and has been effectively used in clinical practice. Due to better preserved natural bone structure, suitable mechanical properties, low immunogenicity, good osteoinductivity and osteoconductivity in natural bone graft, decellularized and demineralized bone matrix (DBM) scaffolds were selected and discussed in the present review. In vivo animal models provide a complex physiological environment for understanding and evaluating material properties and provide important reference data for clinical trials. The purpose of this review is to outline the in vivo bone regeneration and remodeling capabilities of decellularized and DBM scaffolds in bone defect models to better evaluate the potential of these two types of scaffolds in BTE. Taking into account the limitations of the state-of-the-art technology, the results of the animal bone defect model also provide important information for future design of natural bone composite scaffolds.

Repair of a perforated sinus membrane with an autogenous periosteal graft: a study in 24 patients

We describe a technique for repairing a perforation of the sinus membrane with a periosteal graft. Of 117 patients who had augmentation of the sinus floor, the sinus membrane perforated in 24, and these were repaired with autogenous periosteal grafts. Patients were followed up daily for the first 10days and monthly for the next six months, and clinical and radiographic variables were recorded. Patients had to be free of complications such as wound dehiscence, sinus infections, exposure of the graft, local inflammation, or pain. The radiographs showed correct osseointegration of all implants. Periosteal grafts are an effective alternative for repair of a perforation of the sinus membrane.

Innovative use of laterally positioned periosteal pedicle graft for coverage of gingivitis artefacta

There are many etiological factors for nonplaque-induced gingival diseases, out of which physical trauma due to psychiatric reasons leading to self-infliction is less studied upon. This case report presents one such case which has been successfully treated stepwise where psychological counseling was done to restrain from habit followed by using an innovative laterally positioned periosteal pedicle graft for dehiscence coverage.

Mandibular Tissue Engineering: Past, Present, Future

Almost 2 decades ago, the senior author's (M.T.J.) first article was with our mentor, Dr Leonard B. Kaban, a review article titled "Distraction Osteogenesis: Past, Present, Future." In 1998, many thought it would be impossible to have a remotely activated, small, curvilinear distractor that could be placed using endoscopic techniques. Currently, a U.S. patent for a curvilinear automated device and endoscopic techniques for minimally invasive access for jaw reconstruction exist. With minimally invasive access for jaw reconstruction, the burden to decrease donor site morbidity has increased. Distraction osteogenesis (DO) is an in vivo form of tissue engineering. The DO technique eliminates a donor site, is less invasive, requires a shorter operative time than usual procedures, and can be used for multiple reconstruction applications. Tissue engineering could further reduce morbidity and cost and increase treatment availability. The purpose of the present report was to review our experience with tissue engineering of bone: the past, present, and our vision for the future. The present report serves as a tribute to our mentor and acknowledges Dr Kaban for his incessant tutelage, guidance, wisdom, and boundless vision.

A novel bioactive membrane by cell electrospinning

Electrospinning permits fabrication of biodegradable matrices that can resemble the both scale and mechanical behavior of the native extracellular matrix. However, achieving high-cellular density and infiltration of cells within matrices with traditional technique remain challenging and time consuming. The cell electrospinning technique presented in this paper can mitigate the problems associated with these limitations. Cells encapsulated by the material in the cell electrospinning technique survived well and distributed homogenously within the nanofibrous membrane, and their vitality was improved to 133% after being cultured for 28 days. The electrospun nanofibrous membrane has a certain degradation property and favorable cell-membrane interaction that supports the active biocompatibility of the membrane. Its properties are helpful for supporting cell attachment and growth, maintaining phenotypic shape, and secreting an ample amount of extracellular matrix (ECM). This novel membrane may be a potential application within the field of tissue engineering. The ability of cell electrospinning to microintegrate cells into a biodegradable fibrous matrix embodies a novel tissue engineering approach that could be applied to fabricate a high cell density elastic tissue mimetic.

Uncovering the periosteum for skeletal regeneration: the stem cell that lies beneath

The cartilage- and bone-forming properties of the periosteum have long since been recognized. As one of the major sources of skeletal progenitor cells, the periosteum plays a crucial role not only in bone development and growth, but also during bone fracture healing. Aided by the continuous expansion of tools and techniques, we are now starting to acquire more insight into the specific role and regulation of periosteal cells. From a therapeutic point of view, the periosteum has attracted much attention as a cell source for bone tissue engineering purposes. This interest derives not only from the physiological role of the periosteum during bone repair, but is also supported by the unique properties and marked bone-forming potential of expanded periosteum-derived cells. We provide an overview of the current knowledge of periosteal cell biology, focusing on the cellular composition and molecular regulation of this remarkable tissue, as well as the application of periosteum-derived cells in regenerative medicine approaches. This article is part of a Special Issue entitled "Stem Cells and Bone".

Differences in the developmental origins of the periosteum may influence bone healing

BACKGROUND AND OBJECTIVE

The jaw bone, unlike most other bones, is derived from neural crest stem cells, so we hypothesized that it may have different characteristics to bones from other parts of the body, especially in the nature of its periosteum. The periosteum exhibits osteogenic potential and has received considerable attention as a grafting material for the repair of bone and joint defects.

MATERIAL AND METHODS

Gene expression profiles of jaw bone and periosteum were evaluated by DNA microarray and real-time polymerase chain reaction. Furthermore, we perforated an area 2 mm in diameter on mouse frontal and parietal bones. Bone regeneration of these calvarial defects was evaluated using microcomputed tomography and histological analysis.

RESULTS

The DNA microarray data revealed close homology between the gene expression profiles within the ilium and femur. The gene expression of Wnt-1, SOX10, nestin, and musashi-1 were significantly higher in the jaw bone than in other locations. Microcomputed tomography and histological analysis revealed that the jaw bone had superior bone regenerative abilities than other bones.

CONCLUSION

Jaw bone periosteum exhibits a unique gene expression profile that is associated with neural crest cells and has a positive influence on bone regeneration when used as a graft material to repair bone defects. A full investigation of the biological and mechanical properties of jaw bone as an alternative graft material for jaw reconstructive surgery is recommended.

Vestibular deepening by periosteal fenestration and its use as a periosteal pedicle flap for root coverage

Gingival recession along with reduced width of attached gingiva and inadequate vestibular depth is a very common finding. Multiple techniques have been developed to obtain predictable root coverage and to increase the width of attached gingiva. Usually, the width of gingiva is first increased and then the second surgery is caried out for root coverage. The newer methods of root coverage are needed, not only to reconstruct the lost periodontal tissues but also to increase predictability, reduce the number of surgical sites, reduce the number of surgeries and improve patient comfort. Hence, this paper describes a single stage technique for increasing the width of attached gingiva and root coverage by using the periosteal pedicle flap.

Engineering vascularized bone: osteogenic and proangiogenic potential of murine periosteal cells

One of the key challenges in bone tissue engineering is the timely formation of blood vessels that promote the survival of the implanted cells in the construct. Fracture healing largely depends on the presence of an intact periosteum but it is still unknown whether periosteum-derived cells (PDC) are critical for bone repair only by promoting bone formation or also by inducing neovascularization. We first established a protocol to specifically isolate murine PDC (mPDC) from long bones of adult mice. Mesenchymal stem cells were abundantly present in this cell population as more than 50% of the mPDC expressed mesenchymal markers (CD73, CD90, CD105, and stem cell antigen-1) and the cells exhibited trilineage differentiation potential (chondrogenic, osteogenic, and adipogenic). When transplanted on a collagen-calcium phosphate scaffold in vivo, mPDC attracted numerous blood vessels and formed mature bone which comprises a hematopoiesis-supportive stroma. We explored the proangiogenic properties of mPDC using in vitro culture systems and showed that mPDC promote the survival and proliferation of endothelial cells through the production of vascular endothelial growth factor. Coimplantation with endothelial cells demonstrated that mPDC can enhance vasculogenesis by adapting a pericyte-like phenotype, in addition to their ability to stimulate blood vessel ingrowth from the host. In conclusion, these findings demonstrate that periosteal cells contribute to fracture repair, not only through their strong osteogenic potential but also through their proangiogenic features and thus provide an ideal cell source for bone regeneration therapies.

A novel approach to human cranial tissue regeneration and frontal sinus obliteration with an autogenous platelet-rich/fibrin-rich composite matrix: 10 patients with a 6-10 year follow-up

Advanced frontal sinus disease non-responsive to conservative therapy has been treated with fat obliteration for decades. More recently, a wide variety of autogenous, allogenic or synthetic materials have also been used. In this study we present a treatment based on totally autogenous procedures and materials that was successfully implemented in 10 patients and followed up for a period of 6-10 years, to evaluate the feasibility of a new approach for the treatment of frontal sinus disease and other related cranial osseous derangements, based on regenerative medicine as an alternative to fat or other obliterating or grafting materials. Platelet-rich and -poor plasma (PRP, PPP) are set to clot with cortical shavings from the skull surface. After surgically stimulating the sinus to encourage cell chemotaxis, migration and homing, the bioactive scaffold is placed and covered with a PPP membrane and a periosteal flap. Ten patients with pathologies ranging from devastating infection to invasive tumours or trauma were treated with this regenerative procedure in a single-stage surgery. All patients had an uneventful recovery with bone formation and no complications or recurrences over the years. The application of modern principles in tissue regeneration and wound healing has resulted in a favourable outcome, with no complications or sequelae, in a series of 10 patients with advanced frontal sinus disease over a long period of time.

The association of human primary bone cells with biphasic calcium phosphate (βTCP/HA 70:30) granules increases bone repair

This work evaluates the suitability of biphasic calcium phosphate (BCP) granules (β-TCP/HA 70:30) as potential carriers for cell-guided bone therapy. The BCP granules were obtained by synthesis in the presence of wax, thermal treatment, crushing and sieving and characterized by scanning electron microscopy (SEM), X-ray diffraction and Fourier transform infrared spectroscopy. The cytocompatibility of the BCP granules was confirmed by a multiparametric cytotoxicity assay. SEM analysis showed human bone cell adhesion and migration after seeding onto the material. Rat subcutaneous xenogeneic grafting of granules associated to human bone cells revealed a more accentuated moderate chronic inflammatory infiltrate, without signs of a strong xenoreactivity. Histomorphometrical analysis of bone repair of defects in rat skulls (∅ = 5 mm) has shown that bone cell associated-BCP and autograft promoted a two- and threefold increase, respectively, on new bone formation after 45 days, as compared to BCP alone and blood clot. The increase in bone repair supports the suitability the biocompatible (70:30) BCP granules as injectable and mouldable scaffolds for human cells in bone bioengineering.

ECM remodelling components regulated during jaw periosteal cell osteogenesis

Human JPCs (jaw periosteal cells) are a promising source for the engineering of cell-based osteoinductive grafts in oral surgery. For this purpose, cell characteristics of this stem cell source should be elucidated in detail. Analysis of gene expression profiles may help us to evaluate key factors and cellular targets of JPC osteogenesis. Because little is known about the interplay of osteogenic-related components, we analysed the expression of different collagen types reflecting important players for extracellular matrix assembly and of TIMPs (tissue inhibitors of metalloproteinases) responsible for the inhibition of matrix degradation. Gene expression analyses using microarrays and quantitative RT-PCR (reverse transcription-PCR) during JPC osteogenesis revealed the induction of several collagen types' expression (VII, VIII, XI and XII), and some of them (types I, VIII and XI) seemed to be susceptible to BMP-2 (bone morphogenetic protein-2) that is known to be a potent osteogenic inducer of periosteal cells. Among the TIMPs, only TIMP-4 and RECK (reversion-inducing cysteine-rich protein with Kazal motifs) expressions were strongly up-regulated during JPC osteogenesis. Proteome profiler analysis of supernatants from untreated and differentiated JPCs confirmed the gene expression data in terms of TIMP expression. In summary, we identified new collagen types and TIMPs that seem to play important roles during the osteogenesis of jaw periosteal progenitor cells.

Periosteal-derived cells for bone bioengineering: a promising candidate

PURPOSE

Over the last years so many efforts have been made in order to indentify natural sources of osteogenic cells for the success of bone bioengineering. Among them, periosteum tissue has emerged as an interesting candidate. Thus, we decided to evaluate the osteogenic potential of periosteal-derived cells by describing a sequence of biological events since initial morphological changes to mineralization of extracellular matrix (ECM).

METHODS

Periosteal-derived cells were obtained from calvarial of adult rats. After the primary culture and expansion, the adherent cells were cultured at 7, 14, 21 and 28 days under a classical osteogenic culture medium in order to evaluate the differentiation of those cells in mature osteoblast. It was monitored by evaluating a time-line of alkaline phosphatase (ALP) activity (biomarker of osteoblast differentiation) and afterwards nodules of mineralization (measured by von Kossa staining and calcium content).

RESULTS

Analysis from phase-contrast microscopy revealed mainly morphological changes ranging since fibroblast-shaped (7 days, semi-confluent culture at exponential growth) to polyhedral-shaped cells (14-28 days, confluent culture during differentiation process). ALP activity was linearly increased since 14-28 days while amount of protein remained unchanged. Interesting, our data from von Kossa staining reveled a highest incidence of mineralization nodules at 28 days.

CONCLUSION

Taken our results together, we can suggest that periosteal-derived cells present an interesting potential to differentiate in mature osteoblast able to promote mineralization in vitro by incorporating to ECM circulating calcium from extracellular compartment. From our point of view, this source of osteogenic cells can be explored by bioengineers in order to advance therapeutic protocols able to solve bone degenerative lesions.

Repair of critical-size defects with autogenous periosteum-derived cells combined with bovine anorganic apatite/collagen: an experimental study in rat calvaria

The aim of this study was to evaluate the bone repair using autogenous periosteum-derived cells (PDC) and bovine anorganic apatite and collagen (HA-COL). PDC from Wistar rats (n=10) were seeded on HA-COL discs and subjected to osteoinduction during 6 days. Critical-size defects in rat calvarias were treated with blood clot (G1), autogenous bone (G2), HA-COL (G3) and HA-COL combined with PDC (G4) (n=40), and then analyzed 1 and 3 months after surgeries. Radiographic analysis exhibited no significant temporal change. G1 and G2 had discrete new marginal bone, but the radiopacity of graft materials in G2, G3 and G4 impaired the detection of osteogenesis. At 3 months, histopathological analysis showed the presence of ossification islets in G1, which was more evident in G2, homogeneous new bone around HA-COL in G3 and heterogeneous new bone around HA-COL in G4 in addition to moderate presence of foreign body cells in G3 and G4. Histomorphometric analysis showed no change in the volume density of xenograft (p>0.05) and bone volume density in G2 was twice greater than in G1 and G4 after 3 months (p<0.05), but similar to G3. The PDC did not increase bone formation in vivo, although the biomaterial alone showed biocompatibility and osteoconduction capacity.

Periosteum: a highly underrated tool in dentistry

The ultimate goal of any dental treatment is the regeneration of lost tissues and alveolar bone. Under the appropriate culture conditions, periosteal cells secrete extracellular matrix and form a membranous structure. The periosteum can be easily harvested from the patient's own oral cavity, where the resulting donor site wound is invisible. Owing to the above reasons, the periosteum offers a rich cell source for bone tissue engineering; hence, the regenerative potential of periosteum is immense. Although the use of periosteum as a regenerative tool has been extensive in general medical field, the regenerative potential of periosteum is highly underestimated in dentistry; therefore, the present paper reviews the current literature related to the regenerative potential of periosteum and gives an insight to the future use of periosteum in dentistry.

Dimensional change of the healed periosteum on surgically created defects

PURPOSE

The final goal of regenerative periodontal therapy is to restore the structure and function of the periodontium destroyed or lost due to periodontitis. However, the role of periosteum in periodontal regeneration was relatively neglected while bone repair in the skeleton occurs as a result of a significant contribution from the periosteum. The aim of this study is to understand the histological characteristics of periosteum and compare the native periosteum with the repaired periosteum after elevating flap or after surgical intervention with flap elevation.

METHODS

Buccal and lingual mucoperiosteal flaps were reflected to surgically create critical-size, "box-type" (4 mm width, 5 mm depth), one-wall, intrabony defects at the distal aspect of the 2nd and the mesial aspect of the 4th mandibular premolars in the right and left jaw quadrants. Animals were sacrificed after 24 weeks.

RESULTS

THE RESULTS FROM THIS STUDY ARE AS FOLLOWS: 1) thickness of periosteum showed difference as follows (P<0.05): control group (0.45±0.22 mm)>flap-elevation group (0.36±0.07 mm)>defect formation group (0.26±0.03 mm), 2) thickness of gingival tissue showed difference as follows (P<0.05): defect formation group (3.15±0.40 mm)>flap-elevation group (2.02±0.25 mm)>control group (1.88±0.27 mm), 3) higher cellular activity was observed in defect formation group and flap-elevation groups than control group, 4) the number of blood vessles was higher in defect formation group than control group.

CONCLUSIONS

In conclusion, prolonged operation with increased surgical trauma seems to decrease the thickness of repaired periosteum and increase the thickness of gingiva. More blood vessles and high cellular activity were observed in defect formation group.

Molecular variations related to the regional differences in periosteal growth at the mandibular ramus

Periosteal growth at human mandibular ramus is characterized by bone apposition at the posterior border and resorption at the anterior border. Molecular control of this regional variation is unclear. This study examined the expression of several molecules involved in bone apposition/resorption at these regions in vivo and in vitro. By using growing pigs as a model, the periosteal growth was assessed at the mandibular ramus by vital staining and histological observations. In parallel, periosteal tissues were harvested and pulverized for RNA and protein extraction. Periosteal cells were also isolated, expanded in osteogenic media, and subjected to a single dose of dynamic tensile strain (0, 5, or 10% magnitude at 0.5 Hz) to examine their responses to mechanical loading. Real-time RT-PCR and Western blot analyses were used to examine mRNA and protein expression from periosteal tissues and cultured cells. Histological observation confirmed an anterior-resorption/posterior-apposition pattern in the pig mandibular ramus. Both in vivo tissue and in vitro cells demonstrated greater mRNA expression of receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG) ratio and bone morphogenetic protein 2 (BMP2) at the anterior region, while OPG expression at the anterior region was lower than the posterior region. In response to the application of a single dose of dynamic tensile strain, cultured periosteal cells appeared to change the expression profile of osteogenic markers but not that of RANKL/OPG and BMP2. These findings suggest that the unique regional variation of periosteal activity at the mandibular ramus is regulated by a differential expression of RANKL/OPG ratio (likely through differential induction of OPG) and BMP2.

Stromal cell-derived factor-1alpha-directed chemoattraction of transiently CXCR4-overexpressing bone marrow stromal cells into functionalized three-dimensional biomimetic scaffolds

Three-dimensional (3D) bone substitute material should not only serve as scaffold in large bone defects but also attract mesenchymal stem cells, a subset of bone marrow stromal cells (BMSCs) that are able to form new bone tissue. An additional crucial step is to attract BMSCs from the surface into deeper structures of 3D porous bone substitute scaffolds. Here we show that transient overexpression of CXCR4 in human BMSCs induced by mRNA transfection enhances stromal cell-derived factor-1alpha (SDF-1alpha)-directed chemotactic capacity to invade internal compartments of porous 3D bone substitute scaffolds in vitro and in vivo. In vitro native BMCSs invaded up to 500 mum into SDF-1alpha-releasing 3D scaffolds, whereas CXCR4-overexpressing BMSCs invaded up to 800 mum within 5 days. In addition, 60% downregulation of endogenous SDF-1 transcription in BMSCs by endoribonuclease-prepared siRNA before CXCR4 mRNA transfection enhanced SDF-1alpha-directed migration of human BMSCs by 50%. Implantation of SDF-1alpha-releasing scaffolds seeded with transiently CXCR4-overexpressing BMSCs resulted in an increase of invasion into internal compartments of the scaffolds in a mouse model. In vivo native BMCS invaded up to 250 mum into SDF-1alpha-releasing 3D scaffolds, whereas CXCR4-overexpressing BMSC invaded up to 500 mum within 5 days. Thus, the SDF-1alpha/CXCR4 chemoattraction system can be used to efficiently recruit BMSCs into SDF-1alpha-releasing 3D scaffolds in vitro and in vivo.

Periosteal pedicle graft for the treatment of gingival recession defects: a novel technique

BACKGROUND

The periosteum is a highly cellular connective tissue with rich vascularity and regenerative potential. These qualities make it a suitable autogenous graft. A technique utilizing autogenous periosteal pedicle graft (PPG) for the treatment of gingival recession defects is described.

METHODS

Four patients with Miller Class I and II recessions > or = 3 mm were treated utilizing PPG.

RESULTS

At the end of one year, all defects were completely covered.

CONCLUSIONS

The PPG technique can be used for the treatment of gingival recession defects successfully.

The periosteum as a cellular source for functional tissue engineering

The periosteum, a specialized fibrous tissue composed of fibroblast, osteoblast, and progenitor cells, may be an optimal cell source for tissue engineering based on its accessibility, the ability of periosteal cells to proliferate rapidly both in vivo and in vitro, and the observed differentiation potential of these cells. However, the functional use of periosteum-derived cells as a source for tissue engineering requires an understanding of the ability of such cells to elaborate matrix of different tissues. In this study, we subjected a population of adherent primary periosteum-derived cells to both adipogenic and osteogenic culture conditions. The commitment propensity of periosteal cells was contrasted with that of well-characterized phenotypically pure populations of NIH3T3 fibroblast and MC3T3-E1 osteoblast cell lines. Our results demonstrate that the heterogeneous populations of periosteal cells and NIH3T3 fibroblasts have the ability to express both osteoblast-like and adipocyte-like markers with similar potential. This raises the question of whether fibroblasts within the periosteum may, in fact, have the potential to behave like progenitor cells and play a role in the tissue's multilineage potential or whether there are true stem cells within the periosteum. Further, this study suggests that expanded periosteal cultures may be a source for tissue engineering applications without extensive enrichment or sorting by molecular markers. Thus, this study lays the groundwork for future investigations that will more deeply enumerate the cellular sources and molecular events governing periosteal cell differentiation.

Bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) transfection to human periosteal cells enhances osteoblast differentiation and bone formation

Periosteum has been demonstrated to contain mesenchymal progenitor cells differentiating to osteoblasts, and both bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) may play important roles in cell-based approaches to bone regeneration. The purpose of this study was to evaluate the feasibility and efficacy of BMP-2 and/or VEGF on periosteal cell differentiation to osteoblasts in vitro and ectopic bone formation in vivo. Human periosteum-derived cells were transfected with BMP-2, VEGF, BMP-2 + VEGF, or vehicle as a control by non-viral gene transfer and then cultured and implanted to nude mice intramuscularly. Real-time polymerase chain reaction analysis of the culture revealed that transgenes for BMP-2 and BMP-2 + VEGF induced more mRNA expression of alkaline phosphatase, collagen type I, and osteocalcin than VEGF and vehicle treatments; additionally, alizarin red S staining, alkaline phosphatase staining, and alkaline phosphatase activity were significantly higher in the BMP-2 + VEGF transgene than in the other versions. After implantation, ectopic bone was observed at 4 weeks and greatly increased at 8 weeks in all groups. In particular, the combination of BMP-2 and VEGF formed significantly more bone at 4 weeks, and VEGF transfection resulted in more blood vessels relative to the conditions without VEGF. Thus, VEGF might enhance BMP2-induced bone formation through modulation of angiogenesis.

Tissue-engineered cultured periosteum used with platelet-rich plasma and hydroxyapatite in treating human osseous defects

BACKGROUND

The aim of the present controlled clinical study was to compare the clinical response of human cultured periosteum (HCP) sheets in combination with platelet-rich plasma (PRP) and porous hydroxyapatite (HA) granules to a mixture of PRP and HA in the treatment of human infrabony periodontal defects.

METHODS

Thirty interproximal infrabony osseous defects in 30 healthy, non-smoking subjects diagnosed with chronic periodontitis were included in this study. The subjects were randomly assigned to the test group (HCP sheets combined with PRP and HA) or the control group (PRP with HA). Clinical and radiographic measurements were made at baseline and the 12-month post-surgical evaluation.

RESULTS

Compared to baseline, the 12-month results indicated that both treatment modalities resulted in statistically significant changes (P <0.01) in the gingival index, bleeding on probing, probing depth, clinical attachment level, and radiographic infrabony defect depth. Compared to the control group, the test group exhibited a statistically significantly more favorable change in clinical attachment gain (3.9 +/- 1.6 mm versus 2.7 +/- 1.3 mm; P <0.05), vertical relative attachment gain (83.5% +/- 31.7% versus 55.0% +/- 21.9%; P <0.05), and radiographic infrabony defect fill (4.9 +/- 1.2 mm versus 3.2 +/- 1.1 mm; P <0.01).

CONCLUSIONS

Compared to PRP with HA, treatment with a combination of HCP sheets, PRP, and HA led to a significantly more favorable clinical improvement in infrabony periodontal defects. A factor likely contributing to these favorable clinical results is the presence of osteogenic cells in the HCP sheets, which provided greater regeneration potential.