Journal of Oral and Maxillofacial Surgery, Oct 1, 2005
... DDS, MS, Drexel Hill, PA; Lanny R. Garvar, DMD, Tamarac, FL; Michael S. Goldwasser, DDS, MD, ... more ... DDS, MS, Drexel Hill, PA; Lanny R. Garvar, DMD, Tamarac, FL; Michael S. Goldwasser, DDS, MD, Urbana, IL; Scott J. Hollister, PhD, Ann ... DDS, Atlanta, GA; Trevor E. Treasure, DDS, MD, MBA, Indianapolis, IN; James M. Van Ess, DDS, MD, Rochester, MN; Matthew B. Wheeler ...
... This data was then employed to generate a three-dimensional surface mesh of the ... Monte Car... more ... This data was then employed to generate a three-dimensional surface mesh of the ... Monte Carlo (MC) simulations are the current “gold standard” for quantitative description of photon ... To simulate photon propagation in complex tissues, the pre-existing MC code was translated to ...
The Chinese journal of dental research : the official journal of the Scientific Section of the Chinese Stomatological Association, 2018
Objective: To develop a bioreactor for automated culture, maintenance, and collection of normal h... more Objective: To develop a bioreactor for automated culture, maintenance, and collection of normal human keratinocytes using an enzyme-free propagation method. Methods: The culture of normal human epithelial keratinocytes was compared in two culture methods - a study team-developed automated bioreactor utilising an enzyme-free passage method, and a manual culture method. Cell size, glucose utilisation, and the proliferative capacity of the two cultures were evaluated. Results: An automated bioreactor, not using enzymes for passage, but instead using the novel Epithelial Pop Up Keratinocytes (ePUK)1 culture technique, resulted in an extended culture longevity and proliferative capacity in normal primary human keratinocytes. Daughter cells were collected up to three times per day utilising the bioreactor. The daughter cells produced by the bioreactor were smaller than daughter cells produced by the manual culture method. The proliferative capacity and health of the parent monolayer within both the bioreactor and the manual culture flask was dependent upon sufficient glucose availability. Due to the contact inhibition nature of epithelial keratinocytes, the bioreactor enabled the study of an adherent cell type soon after cytokinesis and before the cell has integrated as part of an adherent matrix. Conclusion: The study demonstrates that increasing the number of media changes per day as necessary, based on glucose utilisation, is necessary for prolonged longevity and functional productivity of ePUK cultures.
Purpose One of the most difficult regions of the face to reconstruct after avulsion is the oral r... more Purpose One of the most difficult regions of the face to reconstruct after avulsion is the oral region, specifically the lips, due to the complex natural architecture of the lost tissue (compromising skin, oral mucosa and muscle tissue) that is very difficult to replace. At present the surgical procedures to address this issue has been unsatisfactory. The only other alternative is face transplants which requires lifelong immunosuppression of the recipient. The ability to develop “designer” vascularized prefabrication flap will increase the options available to a reconstructive surgeon. Flap prefabrication would allow the reconstructive surgeon to choose an uninjured wound bed with adequate tissue characteristics, an appropriate set of vessels and place for the construct. Material and methods This tissue engineered muco-cutaneous (M/C) equivalent was manufactured using human oral and skin keratinocytes grown in vitro on an acellular, nonimmunogenic dermal equivalent (AlloDerm) to produce a tissue equivalent with similar anatomic and handling properties as native human lips. Results Confirmation of the structural composition of the construct was performed using routine histology and immunohistochemistry by identification of epithelial markers that are differentially expressed in separate anatomic areas of the lips. We were able to show that there were three distinct anatomical phenotypic regions on the M/C construct; skin, vermillion and oral mucosa. Conclusions We report for the first time the fabrication of a three-dimensional tissue structure containing, in a continuous layer, the morphological features of a lip: epidermal skin, vermillion, and oral mucosa. These full-thickness human lip skin equivalents can be used in surgical lip reconstruction in individuals suffering from lip loss from cancer, congenital deformations, and injuries after accidents. We propose this technique can be used as a general basis for tissue engineering of M/C junctions in other parts of the body, such as anus and vagina.
Craniomaxillofacial soft tissue reconstruction is necessary to restore tissue defects caused by t... more Craniomaxillofacial soft tissue reconstruction is necessary to restore tissue defects caused by trauma, diseases, tumor removal, or congenital abnormality. The use of autologous native tissue will cause a second morbidity to the patient, especially when a large native tissue is required to repair the defect. The application of autologous tissue-engineered devices becomes a logical therapeutic consideration. The recent successful identification of oral and skin stem/progenitor cells and the improvement of scaffolds make it possible to manufacture various types of soft tissue-engineered devices and provide surgeons the materials to restore different areas of soft tissue defects. For craniomaxillofacial soft tissue reconstruction, we should consider esthetics and function in addition to merely anatomical tissue restoration. The ex vivo manufacture and post-manufacture manipulation of the tissue-engineered devices to create a custom-designed product before implantation into a recipient are important to achieve these goals. In this chapter, we report and discuss the concepts and protocols for craniomaxillofacial soft tissue reconstruction with special emphasis on tissue engineering functional human lips.
Clinical translation of engineered tissue constructs requires noninvasive methods to assess const... more Clinical translation of engineered tissue constructs requires noninvasive methods to assess construct health and viability after implantation in patients. However, current practices to monitor post-implantation construct integration are either qualitative (visual assessment) or destructive (tissue histology). As label-free fluorescence lifetime sensing can noninvasively characterize pre-implantation construct viability, we employed a handheld fluorescence lifetime spectroscopy probe to quantitatively and noninvasively assess tissue constructs that were implanted in a murine model. We designed the system to be suitable for intravital measurements: portability, localization with precise maneuverability, and rapid data acquisition. Our model tissue constructs were manufactured from primary human cells to simulate patient variability and were stressed to create a range of health states. Secreted amounts of three cytokines that relate to cellular viability were measured in vitro to assess pre-implantation construct health. In vivo optical sensing assessed tissue integration of constructs at one-week and three-weeks post-implantation. At one-week post-implantation, optical parameters correlated with in vitro pre-implantation secretion levels of all three cytokines (p < 0.05). This relationship was no longer seen at three-weeks post-implantation, suggesting comparable tissue integration independent of preimplantation health. Histology confirmed re-epithelialization of these constructs independent of pre-implantation health state, supporting the lack of a correlation. These results suggest that clinical optical diagnostic tools based on label-free fluorescence lifetime sensing of endogenous tissue fluorophores could noninvasively monitor post-implantation integration of engineered tissues.
One of the major obstacles that have plagued the reconstruction of the temporomandibular joint (T... more One of the major obstacles that have plagued the reconstruction of the temporomandibular joint (TMJ) has been the adverse reactions seen with the use of alloplastic, non-biologic materials. These inert and passive materials, by themselves, do not respond to normal biochemical or biomechanical signals, which are present in situ within the TMJ. The patient, because of the biologic inertness of these materials, must adapt to the material or mechanical device that has been used. This may result in related complications or compromised functional outcome [1]. The main advantage of a tissue engineered TMJ, in contrast, will allow the patient to biologically remodel, overtime, the implanted prosthesis to their own anatomy during functional movements of the jaw per Wolff’s Law, i.e. form and function are related, thus minimizing compromise of function.
ABSTRACT Accident victims and victims of explosive devices often suffer from complex maxillofacia... more ABSTRACT Accident victims and victims of explosive devices often suffer from complex maxillofacial injuries. The lips are one of the most difficult areas of the face to reconstruct after an avulsion. Lip avulsion results in compromised facial esthetics and functions of speech and mastication. The process of reconstruction requires assessment of the vascularization of grafted ex vivo engineered tissue while it is buried underneath the skin. We describe the design and animal testing of a hand-held surgical probe based upon diffuse correlation spectroscopy to assess vascularization.
Fluorescence lifetime imaging microscopy (FLIM) was employed to noninvasively characterize metabo... more Fluorescence lifetime imaging microscopy (FLIM) was employed to noninvasively characterize metabolic function in primary human oral keratinocytes used to develop functional engineered tissues. Living cells were compared under control culture conditions and systematic variations to investigate cellular function and viability. Nonlinear optical microscopy via two-photon excitation was employed to image cellular metabolic biomarkers NAD(P)H and FAD with thin optical sectioning and minimal out-of-focus fluorophore photobleaching. Novel post-processing FLIM algorithms were developed and tested. Results suggest that FLIM may provide useful information about live cell function and viability.
Journal of Oral and Maxillofacial Surgery, Oct 1, 2005
... DDS, MS, Drexel Hill, PA; Lanny R. Garvar, DMD, Tamarac, FL; Michael S. Goldwasser, DDS, MD, ... more ... DDS, MS, Drexel Hill, PA; Lanny R. Garvar, DMD, Tamarac, FL; Michael S. Goldwasser, DDS, MD, Urbana, IL; Scott J. Hollister, PhD, Ann ... DDS, Atlanta, GA; Trevor E. Treasure, DDS, MD, MBA, Indianapolis, IN; James M. Van Ess, DDS, MD, Rochester, MN; Matthew B. Wheeler ...
... This data was then employed to generate a three-dimensional surface mesh of the ... Monte Car... more ... This data was then employed to generate a three-dimensional surface mesh of the ... Monte Carlo (MC) simulations are the current “gold standard” for quantitative description of photon ... To simulate photon propagation in complex tissues, the pre-existing MC code was translated to ...
The Chinese journal of dental research : the official journal of the Scientific Section of the Chinese Stomatological Association, 2018
Objective: To develop a bioreactor for automated culture, maintenance, and collection of normal h... more Objective: To develop a bioreactor for automated culture, maintenance, and collection of normal human keratinocytes using an enzyme-free propagation method. Methods: The culture of normal human epithelial keratinocytes was compared in two culture methods - a study team-developed automated bioreactor utilising an enzyme-free passage method, and a manual culture method. Cell size, glucose utilisation, and the proliferative capacity of the two cultures were evaluated. Results: An automated bioreactor, not using enzymes for passage, but instead using the novel Epithelial Pop Up Keratinocytes (ePUK)1 culture technique, resulted in an extended culture longevity and proliferative capacity in normal primary human keratinocytes. Daughter cells were collected up to three times per day utilising the bioreactor. The daughter cells produced by the bioreactor were smaller than daughter cells produced by the manual culture method. The proliferative capacity and health of the parent monolayer within both the bioreactor and the manual culture flask was dependent upon sufficient glucose availability. Due to the contact inhibition nature of epithelial keratinocytes, the bioreactor enabled the study of an adherent cell type soon after cytokinesis and before the cell has integrated as part of an adherent matrix. Conclusion: The study demonstrates that increasing the number of media changes per day as necessary, based on glucose utilisation, is necessary for prolonged longevity and functional productivity of ePUK cultures.
Purpose One of the most difficult regions of the face to reconstruct after avulsion is the oral r... more Purpose One of the most difficult regions of the face to reconstruct after avulsion is the oral region, specifically the lips, due to the complex natural architecture of the lost tissue (compromising skin, oral mucosa and muscle tissue) that is very difficult to replace. At present the surgical procedures to address this issue has been unsatisfactory. The only other alternative is face transplants which requires lifelong immunosuppression of the recipient. The ability to develop “designer” vascularized prefabrication flap will increase the options available to a reconstructive surgeon. Flap prefabrication would allow the reconstructive surgeon to choose an uninjured wound bed with adequate tissue characteristics, an appropriate set of vessels and place for the construct. Material and methods This tissue engineered muco-cutaneous (M/C) equivalent was manufactured using human oral and skin keratinocytes grown in vitro on an acellular, nonimmunogenic dermal equivalent (AlloDerm) to produce a tissue equivalent with similar anatomic and handling properties as native human lips. Results Confirmation of the structural composition of the construct was performed using routine histology and immunohistochemistry by identification of epithelial markers that are differentially expressed in separate anatomic areas of the lips. We were able to show that there were three distinct anatomical phenotypic regions on the M/C construct; skin, vermillion and oral mucosa. Conclusions We report for the first time the fabrication of a three-dimensional tissue structure containing, in a continuous layer, the morphological features of a lip: epidermal skin, vermillion, and oral mucosa. These full-thickness human lip skin equivalents can be used in surgical lip reconstruction in individuals suffering from lip loss from cancer, congenital deformations, and injuries after accidents. We propose this technique can be used as a general basis for tissue engineering of M/C junctions in other parts of the body, such as anus and vagina.
Craniomaxillofacial soft tissue reconstruction is necessary to restore tissue defects caused by t... more Craniomaxillofacial soft tissue reconstruction is necessary to restore tissue defects caused by trauma, diseases, tumor removal, or congenital abnormality. The use of autologous native tissue will cause a second morbidity to the patient, especially when a large native tissue is required to repair the defect. The application of autologous tissue-engineered devices becomes a logical therapeutic consideration. The recent successful identification of oral and skin stem/progenitor cells and the improvement of scaffolds make it possible to manufacture various types of soft tissue-engineered devices and provide surgeons the materials to restore different areas of soft tissue defects. For craniomaxillofacial soft tissue reconstruction, we should consider esthetics and function in addition to merely anatomical tissue restoration. The ex vivo manufacture and post-manufacture manipulation of the tissue-engineered devices to create a custom-designed product before implantation into a recipient are important to achieve these goals. In this chapter, we report and discuss the concepts and protocols for craniomaxillofacial soft tissue reconstruction with special emphasis on tissue engineering functional human lips.
Clinical translation of engineered tissue constructs requires noninvasive methods to assess const... more Clinical translation of engineered tissue constructs requires noninvasive methods to assess construct health and viability after implantation in patients. However, current practices to monitor post-implantation construct integration are either qualitative (visual assessment) or destructive (tissue histology). As label-free fluorescence lifetime sensing can noninvasively characterize pre-implantation construct viability, we employed a handheld fluorescence lifetime spectroscopy probe to quantitatively and noninvasively assess tissue constructs that were implanted in a murine model. We designed the system to be suitable for intravital measurements: portability, localization with precise maneuverability, and rapid data acquisition. Our model tissue constructs were manufactured from primary human cells to simulate patient variability and were stressed to create a range of health states. Secreted amounts of three cytokines that relate to cellular viability were measured in vitro to assess pre-implantation construct health. In vivo optical sensing assessed tissue integration of constructs at one-week and three-weeks post-implantation. At one-week post-implantation, optical parameters correlated with in vitro pre-implantation secretion levels of all three cytokines (p < 0.05). This relationship was no longer seen at three-weeks post-implantation, suggesting comparable tissue integration independent of preimplantation health. Histology confirmed re-epithelialization of these constructs independent of pre-implantation health state, supporting the lack of a correlation. These results suggest that clinical optical diagnostic tools based on label-free fluorescence lifetime sensing of endogenous tissue fluorophores could noninvasively monitor post-implantation integration of engineered tissues.
One of the major obstacles that have plagued the reconstruction of the temporomandibular joint (T... more One of the major obstacles that have plagued the reconstruction of the temporomandibular joint (TMJ) has been the adverse reactions seen with the use of alloplastic, non-biologic materials. These inert and passive materials, by themselves, do not respond to normal biochemical or biomechanical signals, which are present in situ within the TMJ. The patient, because of the biologic inertness of these materials, must adapt to the material or mechanical device that has been used. This may result in related complications or compromised functional outcome [1]. The main advantage of a tissue engineered TMJ, in contrast, will allow the patient to biologically remodel, overtime, the implanted prosthesis to their own anatomy during functional movements of the jaw per Wolff’s Law, i.e. form and function are related, thus minimizing compromise of function.
ABSTRACT Accident victims and victims of explosive devices often suffer from complex maxillofacia... more ABSTRACT Accident victims and victims of explosive devices often suffer from complex maxillofacial injuries. The lips are one of the most difficult areas of the face to reconstruct after an avulsion. Lip avulsion results in compromised facial esthetics and functions of speech and mastication. The process of reconstruction requires assessment of the vascularization of grafted ex vivo engineered tissue while it is buried underneath the skin. We describe the design and animal testing of a hand-held surgical probe based upon diffuse correlation spectroscopy to assess vascularization.
Fluorescence lifetime imaging microscopy (FLIM) was employed to noninvasively characterize metabo... more Fluorescence lifetime imaging microscopy (FLIM) was employed to noninvasively characterize metabolic function in primary human oral keratinocytes used to develop functional engineered tissues. Living cells were compared under control culture conditions and systematic variations to investigate cellular function and viability. Nonlinear optical microscopy via two-photon excitation was employed to image cellular metabolic biomarkers NAD(P)H and FAD with thin optical sectioning and minimal out-of-focus fluorophore photobleaching. Novel post-processing FLIM algorithms were developed and tested. Results suggest that FLIM may provide useful information about live cell function and viability.
Uploads
Papers by Stephen Feinberg