Clinical evaluation of anorganic bovine-derived hydroxyapatite matrix/cell-binding peptide (P-15) in the treatment of human infrabony defects

Clinical efficacy and safety of P-15 peptide enhanced bone graft substitute in surgical bone regenerative procedures in adult maxillofacial, spine, and trauma patients : a systematic literature review

Aims

Autologous bone graft (ABG) is considered the 'gold standard' among graft materials for bone regeneration. However, complications including limited availability, donor site morbidity, and deterioration of regenerative capacity over time have been reported. P-15 is a synthetic peptide that mimics the cell binding domain of Type-I collagen. This peptide stimulates new bone formation by enhancing osteogenic cell attachment, proliferation, and differentiation. The objective of this study was to conduct a systematic literature review to determine the clinical efficacy and safety of P-15 peptide in bone regeneration throughout the skeletal system.

Methods

PubMed, Embase, Web of Science, and Cochrane Library were searched for relevant articles on 13 May 2023. The systematic review was reported according to the PRISMA guidelines. Two reviewers independently screened and assessed the identified articles. Quality assessment was conducted using the methodological index for non-randomized studies and the risk of bias assessment tool for randomized controlled trials.

Results

After screening, 28 articles were included and grouped by surgical indication, e.g. maxillofacial procedures (n = 18), spine (n = 9), and trauma (n = 1). Published results showed that P-15 peptide was effective in spinal fusion (n = 7) and maxillofacial (n = 11), with very few clinically relevant adverse events related to P-15 peptide.

Conclusion

This systematic literature review concluded that moderate- (risk of bias, some concern: 50%) to high-quality (risk of bias, low: 46%) clinical evidence exists showing equivalent safety and efficacy in bone regeneration using a P-15 peptide enhanced bone graft substitute compared to ABG. P-15 peptide is safe and effective, resulting in rapid bone formation with a low probability of minor complications.

Periodontal granulation tissue preservation in surgical periodontal disease treatment: a pilot prospective cohort study

Purpose

Methods

Results

Conclusions

Osteogenic Peptides and Attachment Methods Determine Tissue Regeneration in Modified Bone Graft Substitutes

The inclusion of biofunctional molecules with synthetic bone graft substitutes has the potential to enhance tissue regeneration during treatment of traumatic bone injuries. The clinical use of growth factors has though been associated with complications, some serious. The use of smaller, active peptides has the potential to overcome these problems and provide a cost-effective, safe route for the manufacture of enhanced bone graft substitutes. This review considers the design of peptide-enhanced bone graft substitutes, and how peptide selection and attachment method determine clinical efficacy. It was determined that covalent attachment may reduce the known risks associated with growth factor-loaded bone graft substitutes, providing a predictable tissue response and greater clinical efficacy. Peptide choice was found to be critical, but even within recognised families of biologically active peptides, the configurations that appeared to most closely mimic the biological molecules involved in natural bone healing processes were most potent. It was concluded that rational, evidence-based design of peptide-enhanced bone graft substitutes offers a pathway to clinical maturity in this highly promising field.

Clinical effectiveness of anorganic bovine-derived hydroxyapatite matrix/cell-binding peptide grafts for regeneration of periodontal defects: a systematic review and meta-analysis

Aim: To ascertain clinical effectiveness of anorganic bovine-derived hydroxyapatite matrix/cell-binding peptide (ABM/P-15) for regeneration of periodontal defects. Materials & methods: Electronic databases (National Library of Medicine [Medline by PubMed], Cochrane Library [Wiley], CINAHL [EBSCO] and Medline [EBSCO]) were systematically searched up to December 2019. Randomized controlled clinical trials comparing ABM/P-15 grafts to conventional surgery for intrabony and gingival recession defects were included and evaluated intrabony defects including clinical attachment level (CAL), probing depth and gingival recession. Results: A significant gain in CAL (1.37 mm), and reduction in probing depth (1.22 mm) were shown by ABM/P-15 grafts than open flap debridement (p < 0.00001). The subgroup analysis also showed better results for ABM/P-15 grafts in CAL gain for intrabony defects. For furcation and gingival recession defects, no significant difference was seen. Conclusion: The adjunct use of ABM/P-15 grafts in conventional periodontal surgery is useful for periodontal regeneration of intrabony defects.

Regenerative surgery versus access flap for the treatment of intra-bony periodontal defects: A systematic review and meta-analysis

BACKGROUND

The aim of this systematic review was to compare clinical, radiographic and patient-reported outcomes (PROMs) in intra-bony defects treated with regenerative surgery or access flap.

MATERIALS AND METHODS

A systematic review protocol was written following the PRISMA checklist. Electronic and hand searches were performed to identify randomized clinical trials (RCTs) on regenerative treatment of deep intra-bony defects (≥3 mm) with a follow-up of at least 12 months. Primary outcome variables were probing pocket depth (PPD) reduction, clinical attachment level (CAL) gain and tooth loss. Secondary outcome variables were Rec, radiographic bone gain, pocket "closure," PROMs and adverse events. Meta-analysis was carried out when possible. To evaluate treatment effect, odds ratios were combined for dichotomous data and mean differences for continuous data using a random-effect model.

RESULTS

A total of 79 RCTs (88 articles) published from 1990 to 2019 and accounting for 3,042 patients and 3,612 intra-bony defects were included in this systematic review. Only 10 of included studies were rated at low risk of bias. A total of 13 meta-analyses were performed. All regenerative procedures provided adjunctive benefit in terms of CAL gain (1.34 mm; 0.95-1.73) compared with open flap debridement alone. Both enamel matrix derivative (EMD) and guided tissue regeneration (GTR) were superior to OFD alone in improving CAL (1.27 mm; 0.79-1.74 mm and 1.43 mm; 0.76-2.22, respectively), although with moderate-high heterogeneity. Among biomaterials, the addition of deproteinized bovine bone mineral (DBBM) improved the clinical outcomes of both GTR with resorbable barriers and EMD. Papillary preservation flaps enhanced the clinical outcomes. The strength of evidence was low to moderate.

CONCLUSION

EMD or GTR in combination with papillary preservation flaps should be considered the treatment of choice for residual pockets with deep (≥3 mm) intra-bony defects.

The role of peptides in bone healing and regeneration: a systematic review

BACKGROUND

Bone tissue engineering and the research surrounding peptides has expanded significantly over the last few decades. Several peptides have been shown to support and stimulate the bone healing response and have been proposed as therapeutic vehicles for clinical use. The aim of this comprehensive review is to present the clinical and experimental studies analysing the potential role of peptides for bone healing and bone regeneration.

METHODS

A systematic review according to PRISMA guidelines was conducted. Articles presenting peptides capable of exerting an upregulatory effect on osteoprogenitor cells and bone healing were included in the study.

RESULTS

Based on the available literature, a significant amount of experimental in vitro and in vivo evidence exists. Several peptides were found to upregulate the bone healing response in experimental models and could act as potential candidates for future clinical applications. However, from the available peptides that reached the level of clinical trials, the presented results are limited.

CONCLUSION

Further research is desirable to shed more light into the processes governing the osteoprogenitor cellular responses. With further advances in the field of biomimetic materials and scaffolds, new treatment modalities for bone repair will emerge.

Evaluation of anorganic bovine-derived hydroxyapatite matrix/cell binding peptide as a bone graft material in the treatment of human periodontal infrabony defects: A clinico-radiographic study

Background:

Various bone graft materials have been used in the treatment of periodontal defects. A synthetic bone substitute material composed of P-15 with anorganic bone mineral has been scantly studied. Hence, the present study was aimed to evaluate and compare the efficacy of anorganic bovine-derived hydroxyapatite matrix (ABM)/cell binding peptide (P-15) in human periodontal infrabony defects with that of open flap debridement (OFD) alone.

Materials and Methods:

A split-mouth, randomized controlled clinical study was designed to investigate the efficacy of ABM/P-15. In this clinical trial, 10 patients having bilateral periodontal infrabony defects were treated either with ABM/P-15 or OFD and followed for a period of 9 months. At baseline and at 9 months probing pocket depth (PPD), relative attachment level (RAL), depth of a defect, and radiographic bone level were measured; and compared between test and control sites.

Results:

A statistically significant reduction (P < 0.001) in PPD was observed in test sites compared to control sites. Both sites showed a gain in RAL without any significant difference. Similarly, the radiographic evaluation revealed significantly higher radiographic defect fill in test sites as compared to control sites (P < 0.001).

Conclusion:

ABM/P-15 bone graft material appears to be useful and beneficial in the treatment of human periodontal infrabony defects.

Interdisciplinary management of an isolated intrabony defect

The treatment of intrabony defects is a real challenge in molar teeth as it is chronic, slowly progressing disease which needs timely intervention. Periodontal inflammation associated with intrabony defect is not a separate entity as it secondarily affects the pulp causing retrograde pulpitis. However, treatment of these lesions will be complicated due to extensive bone loss. The tooth was endodontically treated followed by periodontal surgery to eliminate the deep periodontal pocket and promote bone fill in osseous defect. PepGen P-15 composited with platelet rich plasma was utilized for enhancing bone formation. The combination of these graft materials provides synergistic effect on bone regeneration.

Efficacy of a small cell-binding peptide coated hydroxyapatite substitute on bone formation and implant fixation in sheep

Cylindrical critical size defects were created at the distal femoral condyles bilaterally of eight female adult sheep. Titanium implants with 2-mm concentric gaps were inserted and the gaps were filled with one of the four materials: allograft; a synthetic 15-amino acid cell-binding peptide coated hydroxyapatite (ABM/P-15); hydroxyapatite + βtricalciumphosphate+ Poly-Lactic-Acid (HA/βTCP-PDLLA); or ABM/P-15+HA/βTCP-PDLLA. After nine weeks, bone-implant blocks were harvested and sectioned for micro-CT scanning, push-out test, and histomorphometry. Significant bone formation and implant fixation could be observed in all four groups. Interestingly, the microarchitecture of the ABM/P-15 group was significantly different from the control group. Tissue volume fraction and thickness were significantly greater in the ABM/P-15 group than in the allograft group. Bone formation and bone ingrowth to porous titanium implant were not significantly different among the four groups. The ABM/P-15 group had similar shear mechanical properties on implant fixation as the allograft group. Adding HA/βTCP-PDLLA to ABM/P-15 did not significantly change these parameters. This study revealed that ABM/P-15 had significantly bone formation in concentric gap, and its enhancements on bone formation and implant fixation were at least as good as allograft. It is suggested that ABM/P-15 might be a good alternative biomaterial for bone implant fixation in this well-validated critical-size defect gap model in sheep. Nevertheless, future clinical researches should focus on prospective, randomized, controlled trials in order to fully elucidate whether ABM/P-15 could be a feasible candidate for bone substitute material in orthopedic practices.

Peptide-based delivery to bone

Peptides are attractive as novel therapeutic reagents, since they are flexible in adopting and mimicking the local structural features of proteins. Versatile capabilities to perform organic synthetic manipulations are another unique feature of peptides compared to protein-based medicines, such as antibodies. On the other hand, a disadvantage of using a peptide for a therapeutic purpose is its low stability and/or high level of aggregation. During the past two decades, numerous peptides were developed for the treatment of bone diseases, and some peptides have already been used for local applications to repair bone defects in the clinic. However, very few peptides have the ability to form bone themselves. We herein summarize the effects of the therapeutic peptides on bone loss and/or local bone defects, including the results from basic studies. We also herein describe some possible methods for overcoming the obstacles associated with using therapeutic peptide candidates.

Influence of different biomaterials on the viability of Aggregatibacter actinomycetemcomitans

OBJECTIVES

The aim of the present in vitro study was to evaluate the effects of different biomaterials used for regenerative periodontal surgery on the growth of the periodontopathogen Aggregatibacter actinomycetemcomitans.

METHODS

Three commercially available biomaterials of synthetic origin (hydroxyapatite/beta-tricalcium phosphate, nanostructured hydroxyapatite paste, oily calcium hydroxide suspension), a bovine-derived xenograft as well as an enamel matrix derivative (EMD) were added in different concentrations to calibrated suspensions of A. actinomycetemcomitans ATCC 43718/33384 (serotype b/c). Equal aliquots (0.1 ml) for the viability assay were taken after 5 min, 1h, 3h, 8h and 24h, plated on blood agar and incubated in an anaerobic environment for 48 h at 37°C. Viable cell counts were expressed as colony forming units (cfu)/0.1 ml.

RESULTS

The results demonstrated that none of the investigated biomaterials could inhibit the growth of A. actinomycetemcomitans serotype b. A marked growth reduction of A. actinomycetemcomitans serotype c was observed in the presence of oily calcium hydroxide suspension and nanostructured hydroxyapatite. In contrast, no significant growth inhibition could be observed in the presence of hydroxyapatite/beta-tricalcium phosphate, enamel matrix derivative and bovine-derived xenograft.

CONCLUSIONS

The results of the present study suggest that none of the investigated biomaterials possesses antimicrobial properties against A. actinomycetemcomitans serotype b. Therefore, the use of these biomaterials for regenerative procedures should be weighted critically in the presence of A. actinomycetemcomitans serotype b.

Evaluation of ABM/P-15 versus autogenous bone in an ovine lumbar interbody fusion model

A prospective, randomized study was performed in an ovine model to compare the efficacy of an anorganic bovine-derived hydroxyapatite matrix combined with a synthetic 15 amino acid residue (ABM/P-15) in facilitating lumbar interbody fusion when compared with autogenous bone harvested from the iliac crest. P-15 is a biomimetic to the cell-binding site of Type-I collagen for bone-forming cells. When combined with ABM, it creates the necessary scaffold to initiate cell invasion, binding, and subsequent osteogenesis. In this study, six adult ewes underwent anterior-lateral interbody fusion at L3/L4 and L4/L5 using PEEK interbody rings filled with autogenous bone at one level and ABM/P-15 at the other level and no additional instrumentation. Clinical CT scans were obtained at 3 and 6 months; micro-CT scans and histomorphometry analyses were performed after euthanization at 6 months. Clinical CT scan analysis showed that all autograft and ABM/P-15 treated levels had radiographically fused outside of the rings at the 3-month study time point. Although the clinical CT scans of the autograft treatment group showed significantly better fusion within the PEEK rings than ABM/P-15 at 3 months, micro-CT scans, clinical CT scans, and histomorphometric analyses showed there were no statistical differences between the two treatment groups at 6 months. Thus, ABM/P-15 was as successful as autogenous bone graft in producing lumbar spinal fusion in an ovine model, and it should be further evaluated in clinical studies.

A review on endogenous regenerative technology in periodontal regenerative medicine

Periodontitis is a globally prevalent inflammatory disease that causes the destruction of the tooth-supporting apparatus and potentially leads to tooth loss. Currently, the methods to reconstitute lost periodontal structures (i.e. alveolar bone, periodontal ligament, and root cementum) have relied on conventional mechanical, anti-infective modalities followed by a range of regenerative procedures such as guided tissue regeneration, the use of bone replacement grafts and exogenous growth factors (GFs), and recently developed tissue engineering technologies. However, all current or emerging paradigms have either been shown to have limited and variable outcomes or have yet to be developed for clinical use. To accelerate clinical translation, there is an ongoing need to develop therapeutics based on endogenous regenerative technology (ERT), which can stimulate latent self-repair mechanisms in patients and harness the host's innate capacity for regeneration. ERT in periodontics applies the patient's own regenerative 'tools', i.e. patient-derived GFs and fibrin scaffolds, sometimes in association with commercialized products (e.g. Emdogain and Bio-Oss), to create a material niche in an injured site where the progenitor/stem cells from neighboring tissues can be recruited for in situ periodontal regeneration. The choice of materials and the design of implantable devices influence therapeutic potential and the number and invasiveness of the associated clinical procedures. The interplay and optimization of each niche component involved in ERT are particularly important to comprehend how to make the desired cell response safe and effective for therapeutics. In this review, the emerging opportunities and challenges of ERT that avoid the ex vivo culture of autologous cells are addressed in the context of new approaches for engineering or regeneration of functional periodontal tissues by exploiting the use of platelet-rich products and its associated formulations as key endogenous resources for future clinical management of periodontal tissue defects.

A clinical comparison of autogenous bone graft with and without autogenous periodontal ligament graft in the treatment of periodontal intrabony defects

The aim of the present study was to evaluate the efficacy of autogenous bone graft (ABG) with and without autogenous periodontal ligament graft (PDLG) in the management of human two-wall intrabony periodontal defects. Twenty-six similar two-wall intrabony periodontal defects with >or=5 mm probing depths and >or=3 mm depths of intrabony component in 13 nonsmoking healthy patients were selected. One defect in each subject was treated with ABG alone (ABG group) and the contralateral one with ABG and PDLG (PDLG group). The primary outcomes of the study included changes in clinical probing depth (CPD) and clinical attachment level (CAL). Groups showed statistically significant improvements in soft and hard tissue parameters after 6 months. However, the between-group differences after 6 months were not statistically significant with regard to soft and hard tissue measurements except CAL gain. In the combined group, it was significantly higher than the ABG group (3.69 and 2 mm, respectively; P = 0.03). Within the limits of this study, both treatments resulted in marked clinical improvement, but combined treatment seemed to enhance the results in the treatment of two-wall intrabony defects.