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| REVIEW ARTICLE |
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| Year : 2022 | Volume
: 9
| Issue : 4 | Page : 99-102 |
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Unfolding the journey of scaffold
Bhumika Jhawar1, Shirish Kujur2, Vineeta Gupta3, Pragya Kumari1, Hungyo Chanreiphy1
1 Post Graduate Student, Department of Periodontics, Government Dental College, Raipur, Chhattisgarh, India
2 Associate Professor, Department of Periodontics, Government Dental College, Raipur, Chhattisgarh, India
3 Professor and HOD, Department of Periodontics, Government Dental College, Raipur, Chhattisgarh, India
| Date of Submission | 18-Dec-2022 |
| Date of Acceptance | 19-Dec-2022 |
| Date of Web Publication | 29-Dec-2022 |
Correspondence Address:
Dr. Bhumika Jhawar
Department of Periodontics, Government Dental College, Raipur, Chhattisgarh
India
 Source of Support: None, Conflict of Interest: None
DOI: 10.4103/ijpcdr.ijpcdr_27_22
Periodontal tissues can be destructed by chronic periodontal disease, which can lead to tooth loss. In support of the treatment for periodontally diseased tooth, various biomaterials have been applied starting as a contact inhibition membrane in the guided tissue regeneration that is the current gold standard in dental clinic. Recently, various biomaterials have been prepared in a form of tissue engineering scaffold to facilitate the regeneration of damaged periodontal tissues. From a physical substrate to support healing of a single type of periodontal tissue to multiphase/bioactive scaffold system to guide an integrated regeneration of periodontium, technologies for scaffold fabrication have emerged in the last years. This review covers the recent advancements in development of scaffolds designed for periodontal tissue regeneration and their efficacy tested in vitro and in vivo.
Keywords: Bioactive scaffold, multiphase scaffold, periodontal regeneration, periodontitis
How to cite this article:
Jhawar B, Kujur S, Gupta V, Kumari P, Chanreiphy H. Unfolding the journey of scaffold. Int J Prev Clin Dent Res 2022;9:99-102 |
How to cite this URL:
Jhawar B, Kujur S, Gupta V, Kumari P, Chanreiphy H. Unfolding the journey of scaffold. Int J Prev Clin Dent Res [serial online] 2022 [cited 2023 Jun 10];9:99-102. Available from: https://www.ijpcdr.org/text.asp?2022/9/4/99/366150 |
| Introduction | |  |
Periodontitis is a microbial infectious disease and is characterized by the presence of gingival inflammation, periodontal pocket formation, and loss of connective tissue attachment and alveolar bone around the affected teeth. The aim of periodontal therapy is to protect and maintain the patient's natural dentition over their lifetime for optimal comfort, function, and esthetic appearance. The ultimate goal of a successful periodontal therapy is regeneration of the lost periodontal tissues. A lot of approaches and techniques such as use of various types of bone grafts, growth factors, and guided tissue regeneration (GTR) are presently being to achieve this goal. The most recent introduction to this context is the concept of tissue engineering using stem cells. The 20th century gave us antibiotics, revolutionary imaging technologies, and most important the silicon chip, which has shrunk the world for us and brought information to our fingertips or mouse tips. The 21st century can be credited with biotechnology, genomics, and last but not the least, tissue engineering.[1],[2]
| Rationale | | |
One of the major goals of periodontal therapy is to encourage the regeneration of tissues that have been destroyed as a result of periodontal disease. Periodontal regeneration is defined as the reproduction or reconstitution of a lost or injured part so that form and function of these structures are restored. However, despite the best that current therapies can offer, the ultimate response of the periodontium depends upon the tissues and cells that participate in the healing process. Although GTR and EMD have been shown to be effective in regenerating a limited range of periodontal defects, such as three wall intrabony defects and Class 2 furcations, currently available clinical techniques are generally unpredictable and cannot be utilized in the vast majority of periodontal defects.[3]
The reasons for failure for most regenerative techniques have been outlined by Bartold et al. (2000):
- Inability to control the formation of a long junctional epithelium
- Inability to adequately seal the healing site from the oral environment and prevent infection
- Inability to maintain the wound as a closed rather than open system
- Restriction of regeneration to the bone compartment while ignoring regenerative processes required for cementogenesis and fibrous attachment
- Inability to define precisely the growth and differentiation factors needed for regeneration
- The possibility that growth factors may not be sufficiently discriminative in their ability to induce regeneration, and thus, the induction of particular transcription factors as an earlier event of cell stimulation may be warranted
- Infection of the implanted membrane or regenerative material postoperatively.
| Tissue Engineering Triad | | |
The tissue engineering approach to bone and periodontal regeneration combines three key elements to enhance regeneration.
- Conductive scaffolds/extracellular matrix
- Signaling molecules
- Stem/progenitor cells
This concept is often represented as a triangle, indicating that by combining the three key elements, tissue regeneration can often be accomplished.[4]
| Scaffold | | |
A scaffold is a permanently or temporarily placed three-dimensional porous and permeable natural or synthetic biomaterial that is biocompatible. It can be natural or synthetic. It acts as a matrix and allows the attachment, migration, and differentiation of progenitor cells. Properties of scaffolds (such as biodegradability, porosity, stiffness, and strength) influence cell adhesion, migration, and proliferation (such as osteoconduction).[5]
A scaffold plays many roles in tissue regeneration process:[6]
- It serves as a framework to support cellular migration into the defect from surrounding tissues
- It serves as a delivery vehicle for exogenous cells, growth factors, and genes
- It may structurally reinforce the defect to maintain the shape of the defect
- It serves as a barrier to prevent infiltration of surrounding tissue that may impede the process of regeneration
- Before its absorption, a scaffold can serve as a matrix for exogenous and endogenous cell adhesion and thus facilitates and regulates certain cellular processes, including mitosis, synthesis, and migration.
The greatest challenges faced in tissue-engineered devices are to promote healing in three dimensions. Scaffolds have been made up with a variety of innate and synthetic biomaterials, such as ceramics, metals, proteins, and polymers. An appropriate scaffold for tissue engineering will be one that is created with biology in mind. The function of the scaffolds is providing structural support to cells, reservoir for growth factors and provide flexible, physical environment for remodeling.[6],[7],[8],[9],[10],[11]
| Biomaterials Used as Scaffolds | | |
| Ideal Design Requirements For Cell Seeding Scaffolds | | |
[9]
Biocompatibility
The cells must adhere, retain normal functioning, and migrate to the surface through the scaffold and proliferate before production of new matrix. After getting implanted, the scaffold must not produce any immune reaction in order to prevent any inflammatory response which may alter the wound healing.[3]
Biodegradability
The aim of tissue engineering is to let the cells of the body to replace the implanted scaffold. The scaffold must degrade biologically to yield their own extracellular matrix. Healing of these tissues must happen under a significant bacterial load and rendered to this complexity is the action of occlusal forces in the transverse and axial planes which affects the pattern of wound healing. Hence, without the introduction of the triad theory, it may be difficult to overcome these limitations.[6],[7],[8],[9],[10],[11]
Mechanical properties
The scaffold properties must be comparable to the anatomical site of placement and should be rigid to allow surgical handling. Researchers face a great challenge to construct a scaffold with suitable mechanical properties to engineer bone. In such cases, the implanted material (scaffold) should have suitable mechanical properties to function from the implanted time to the completion of bone remodeling.[6],[7]
Scaffold architecture
To ensure proper cellular penetration and sufficient nutrition diffusion, the scaffolds must possess an interconnected pore structure and have high porosity. This also ensures proper degradation of the by-products to exit the body without any interference with adjacent tissues. The size of the pores must be such that it can allow cells to migrate into the scaffold where they bind with the ligands within the scaffold and small enough to ensure a specific surface so that only. A certain amount of cells can bind to the scaffold.[5],[6],[7],[8],[9],[10]
Space maintenance within the defect site and barrier functions
The essential design features required for space maintenance include ease of shaping and sufficient rigidity to resist soft tissue collapse into the damaged site and an internal structure compatible with attachment of cell and colonization and allowing the growth of tissues compatible with those to be regenerated.[10],[11],[12]
| Regulating Cell Activity Through Scaffold Design | | |
[10]
It has been recognized for many years that the microenvironment in which a cell resides dictates many functions and phenotypes. Thus, it seems logical that the construction and design of a cell seeding scaffold must take into account microenvironment design features to induce the appropriate gene expression in cells forming new tissues. The control of gene expression by cells within a scaffold can be regulated via interactions with the adhesion surface, with other cells in the vicinity or, as described above, incorporated growth and differentiation factors in the scaffold. Accordingly, cell-seeding scaffolds must provide the correct combination of these factors, according to the tissues to be regenerated, if one is to achieve successful gene expression and tissue regeneration. When considering scaffold design, many tissues depend upon mechanical stimuli to regulate gene expression and thus tissue composition. The most obvious example of this is bone and tendon, although it is likely that the periodontal ligament (PDL) should also be considered in this context. In order to engineer such functional tissues, the correct mechanical stimuli will need to be conveyed to the developing tissues within the cell/scaffold construct. To date, because of the complexities of such systems, very few studies have addressed these issues.[10],[11],[12],[13],[14],[15]
| Challenges | | |
Some of the main challenges for regenerating functional periodontal tissues are listed below: from material perspective, most of the biomaterials used for periodontal regeneration are traditional biomaterials, such as hydroxyapatite, β-trichloropropane, and poly (dl-lactic-co-glycolic acid). Even though these biomaterials can resemble the compositions in certain aspects, they cannot mimic the fine structures of the natural periodontal tissues, such as the different groups of PDL fibers, cellular and acellular cementum structure. One specific challenge is the regeneration of Sharpey's fibers between cementum, PDL, and alveolar bone. Currently, none of the scaffolding systems regenerated functional Sharpey's fibers. Without these fibers, the connections between cementum, PDL, and alveolar bone are unstable and cannot support teeth or bear occlusal force. Therefore, novel and bio-inspired materials that are designed to closely mimic the architecture of periodontal tissues at micro and nanoscale levels are prerequisites to achieve functional periodontal tissue regeneration.[1],[6],[11],[16]
| Conclusion | | |
To regenerate the hierarchical architecture of periodontal tissues, spatially and temporally controlled delivery of biophysical and biochemical cues is indispensable. While there have been a variety of multidrug delivery systems developed, none of them can achieve precise control to guide periodontal tissue regeneration. There are a number of barriers that hinder optimized tissue regeneration. Another knowledge gap is the proper concentrations of bioactive molecules, because overuse or insufficient drugs/growth factor compromises the outcomes. Therefore, an in-depth understanding of the basic biology is indispensable to provide more detailed information to guide the fabrication of biomimetic materials.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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