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Williams J, Prey B, Francis A, Weykamp M, Liu B, Parsons M, Vu M, Franko J, Roedel E, Horton J, Bingham J, Mentzer S, Kuckelman J. Bioadhesive patch as a parenchymal sparing treatment of acute traumatic pulmonary air leaks. J Trauma Acute Care Surg 2023; 95:679-684. [PMID: 36973876 DOI: 10.1097/ta.0000000000003956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
INTRODUCTION Traumatic pulmonary injuries are common in chest trauma. Persistent air leaks occur in up to 46% of patients depending on injury severity. Prolonged leaks are associated with increased morbidity and cost. Prior work from our first-generation pectin patches successfully sealed pulmonary leaks in a cadaveric swine model. We now test the next-generation pectin patch against wedge resection in the management of air leaks in anesthetized swine. METHODS A continuous air leak of 10% to 20% percent was created to the anterior surface of the lung in intubated and sedated swine. Animals were treated with a two-ply pectin patch or stapled wedge resection (SW). Tidal volumes (TVs) were recorded preinjury and postinjury. Following repair, TVs were recorded, a chest tube was placed, and animals were observed for presence air leak at closure and for an additional 90 minutes while on positive pressure ventilation. Mann-Whitney U test and Fisher's exact test used to compare continuous and categorical data between groups. RESULTS Thirty-one animals underwent either SW (15) or pectin patch repair (PPR, 16). Baseline characteristics were similar between animals excepting baseline TV (SW, 10.3 mL/kg vs. PPR, 10.9 mL/kg; p = 0.03). There was no difference between groups for severity of injury based on percent of TV loss (SW, 15% vs. PPR, 14%; p = 0.5). There was no difference in TV between groups following repair (SW, 10.2 mL/kg vs. PPR, 10.2 mL/kg; p = 1) or at the end of observation (SW, 9.8 mL/kg vs. PPR, 10.2 mL/kg; p = 0.4). One-chamber intermittent air leaks were observed in three of the PPR animals, versus one in the SW group ( p = 0.6). CONCLUSION Pectin patches effectively sealed the lung following injury and were noninferior when compared with wedge resection for the management of acute traumatic air leaks. Pectin patches may offer a parenchymal sparing option for managing such injuries, although studies evaluating biodurability are needed.
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Affiliation(s)
- James Williams
- From the Madigan Army Medical Center (J.W., B.P., A.F., M.W., M.P., M.V., J.F., E.R., J.H., J.B., J.K.), Tacoma, Washington; and Laboratory of Adaptive and Regenerative Biology (B.L., S.M., J.K.), Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
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Liu BS, Liao M, Wagner WL, Khalil HA, Chen Z, Ackermann M, Mentzer SJ. Biomechanics of a Plant-Derived Sealant for Corneal Injuries. Transl Vis Sci Technol 2023; 12:20. [PMID: 37204800 PMCID: PMC10204774 DOI: 10.1167/tvst.12.5.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 04/05/2023] [Indexed: 05/20/2023] Open
Abstract
Purpose The corneal epithelium has a glycocalyx composed of membrane-associated glycoproteins, mucins, and galactin-3. Similar to the glycocalyx in visceral tissues, the corneal glycocalyx functions to limit fluid loss and minimize frictional forces. Recently, the plant-derived heteropolysaccharide pectin has been shown to physically entangle with the visceral organ glycocalyx. The ability of pectin to entangle with the corneal epithelium is unknown. Methods To explore the potential role of pectin as a corneal bioadhesive, we assessed the adhesive characteristics of pectin films in a bovine globe model. Results Pectin film was flexible, translucent, and low profile (80 µm thick). Molded in tape form, pectin films were significantly more adherent to the bovine cornea than control biopolymers of nanocellulose fibers, sodium hyaluronate, and carboxymethyl cellulose (P < 0.05). Adhesion strength was near maximal within seconds of contact. Compatible with wound closure under tension, the relative adhesion strength was greatest at a peel angle less than 45 degrees. The corneal incisions sealed with pectin film were resistant to anterior chamber pressure fluctuations ranging from negative 51.3 ± 8.9 mm Hg to positive 214 ± 68.6 mm Hg. Consistent with these findings, scanning electron microscopy demonstrated a low-profile film densely adherent to the bovine cornea. Finally, the adhesion of the pectin films facilitated the en face harvest of the corneal epithelium without physical dissection or enzymatic digestion. Conclusions We conclude that pectin films strongly adhere to the corneal glycocalyx. Translational Relevance The plant-derived pectin biopolymer provides potential utility for corneal wound healing as well as targeted drug delivery.
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Affiliation(s)
- Betty S. Liu
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Matthew Liao
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Willi L. Wagner
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Diagnostic and Interventional Radiology, Translational Lung Research Center, University of Heidelberg, Heidelberg, Germany
| | - Hassan A. Khalil
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Zi Chen
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Steven J. Mentzer
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
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Floess M, Steinle T, Werner F, Wang Y, Wagner WL, Steinle V, Liu BS, Zheng Y, Chen Z, Ackermann M, Mentzer SJ, Giessen H. 3D stimulated Raman spectral imaging of water dynamics associated with pectin-glycocalyceal entanglement. BIOMEDICAL OPTICS EXPRESS 2023; 14:1460-1471. [PMID: 37078053 PMCID: PMC10110326 DOI: 10.1364/boe.485314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/25/2023] [Accepted: 02/26/2023] [Indexed: 05/03/2023]
Abstract
Pectin is a heteropolysaccharide responsible for the structural integrity of the cell walls of terrestrial plants. When applied to the surface of mammalian visceral organs, pectin films form a strong physical bond with the surface glycocalyx. A potential mechanism of pectin adhesion to the glycocalyx is the water-dependent entanglement of pectin polysaccharide chains with the glycocalyx. A better understanding of such fundamental mechanisms regarding the water transport dynamics in pectin hydrogels is of importance for medical applications, e.g., surgical wound sealing. We report on the water transport dynamics in hydrating glass-phase pectin films with particular emphasis on the water content at the pectin-glycocalyceal interface. We used label-free 3D stimulated Raman scattering (SRS) spectral imaging to provide insights into the pectin-tissue adhesive interface without the confounding effects of sample fixation, dehydration, shrinkage, or staining.
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Affiliation(s)
- Moritz Floess
- 4 Physics Institute and Stuttgart Research Center of Photonic Engineering, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - Tobias Steinle
- 4 Physics Institute and Stuttgart Research Center of Photonic Engineering, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - Florian Werner
- 4 Physics Institute and Stuttgart Research Center of Photonic Engineering, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - Yunshan Wang
- 4 Physics Institute and Stuttgart Research Center of Photonic Engineering, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - Willi L. Wagner
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Im Neuenheimer Feld 420, 69120 Heidelberg, Germany
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Im Neuenheimer Feld 156, 69120 Heidelberg, Germany
| | - Verena Steinle
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Im Neuenheimer Feld 420, 69120 Heidelberg, Germany
| | - Betty S. Liu
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Yifan Zheng
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Zi Chen
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Maximilian Ackermann
- Institute of Pathology and Department of Molecular Pathology, Helios University Clinic Wuppertal, University of Witten-Herdecke, Wuppertal, Germany
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Steven J. Mentzer
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Harald Giessen
- 4 Physics Institute and Stuttgart Research Center of Photonic Engineering, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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Kinetics of Pectin Biopolymer Facial Erosion Characterized by Fluorescent Tracer Microfluidics. Polymers (Basel) 2022; 14:polym14183911. [PMID: 36146055 PMCID: PMC9501333 DOI: 10.3390/polym14183911] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/29/2022] [Accepted: 08/31/2022] [Indexed: 11/16/2022] Open
Abstract
Pectin is a plant-derived heteropolysaccharide that has been implicated in drug development, tissue engineering, and visceral organ repair. Pectin demonstrates remarkable biostability in a variety of physiologic environments but is biodegradable in water. To understand the dynamics of pectin biodegradation in basic environments, we developed a microfluidics system that facilitated the quantitative comparison of pectin films exposed to facial erosion. Pectin biodegradation was assessed using fluorescein tracer embedded in pectin, trypan blue quenching of released fluorescence, and highly sensitive microfluorimetry. The microfluidic perfusate, delivered through 6 um-pore synthetic membrane interface, demonstrated nonlinear erosion of the pectin film; 75% of tracer was released in 28 h. The microfluidics system was used to identify potential modifiers of pectin erosion. The polyphenolic compound tannic acid, loaded into citrus pectin films, demonstrated a dose-dependent decrease in pectin erosion. Tannic acid had no detectable impact on the physical properties of citrus pectin including adhesivity and cohesion. In contrast, tannic acid weakened the burst strength and cohesion of pectins derived from soy bean and potato sources. We conclude that facial erosion may explain the biostability of citrus pectin on visceral organ surfaces as well as provide a useful method for identifying modifiers of citrus pectin biodegradation.
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Eivazzadeh-Keihan R, Noruzi EB, Aliabadi HAM, Sheikhaleslami S, Akbarzadeh AR, Hashemi SM, Gorab MG, Maleki A, Cohan RA, Mahdavi M, Poodat R, Keyvanlou F, Esmaeili MS. Recent advances on biomedical applications of pectin-containing biomaterials. Int J Biol Macromol 2022; 217:1-18. [PMID: 35809676 DOI: 10.1016/j.ijbiomac.2022.07.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/13/2022] [Accepted: 07/03/2022] [Indexed: 12/15/2022]
Abstract
There is a growing demand for biomaterials developing with novel properties for biomedical applications hence, hydrogels with 3D crosslinked polymeric structures obtained from natural polymers have been deeply inspected in this field. Pectin a unique biopolymer found in the cell walls of fruits and vegetables is extensively used in the pharmaceutical, food, and textile industries due to its ability to form a thick gel-like solution. Considering biocompatibility, biodegradability, easy gelling capability, and facile manipulation of pectin-based biomaterials; they have been thoroughly investigated for various potential biomedical applications including drug delivery, wound healing, tissue engineering, creation of implantable devices, and skin-care products.
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Affiliation(s)
- Reza Eivazzadeh-Keihan
- Nanobiotechnology Department, New Technologies Research Group, Pasteur Institute of Iran, Tehran, Iran
| | - Ehsan Bahojb Noruzi
- Faculty of Chemistry, Department of Inorganic Chemistry, University of Tabriz, Tabriz, Iran
| | - Hooman Aghamirza Moghim Aliabadi
- Protein Chemistry Laboratory, Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran; Advanced Chemical Studies Lab, Department of Chemistry, K. N. Toosi University of Technology, Tehran, Iran
| | - Sahra Sheikhaleslami
- Advanced Chemical Studies Lab, Department of Chemistry, K. N. Toosi University of Technology, Tehran, Iran
| | - Ali Reza Akbarzadeh
- Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran
| | - Seyed Masoud Hashemi
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran
| | - Mostafa Ghafori Gorab
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran
| | - Ali Maleki
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran.
| | - Reza Ahangari Cohan
- Nanobiotechnology Department, New Technologies Research Group, Pasteur Institute of Iran, Tehran, Iran
| | - Mohammad Mahdavi
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
| | - Roksana Poodat
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran
| | - Faeze Keyvanlou
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran
| | - Mir Saeed Esmaeili
- Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Iran
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Zhou S, Luo F, Gu M, Lu X, Xu Y, Wu R, Xiong J, Ran X. Biopsy-tract haemocoagulase injection reduces major complications after CT-guided percutaneous transthoracic lung biopsy. Clin Radiol 2022; 77:e673-e679. [PMID: 35788268 DOI: 10.1016/j.crad.2022.05.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/11/2022] [Accepted: 05/20/2022] [Indexed: 11/03/2022]
Abstract
AIM To determine whether the injection of haemocoagulase into the biopsy tract can reduce pneumothorax and pulmonary haemorrhage after computed tomography (CT)-guided percutaneous transthoracic lung biopsy (PTLB). MATERIALS AND METHODS A retrospective study was performed involving patients with undiagnosed pulmonary lesions scheduled for PTLB between January 2020 and March 2021. Patients were assigned to the haemocoagulase group or the non-haemocoagulase group. After CT-guided biopsies were performed with a 17 G coaxial system, patients in the haemocoagulase group received a haemocoagulase injection (0.2-0.5 units) in the biopsy tract as the sheath was withdrawn. Postoperative image studies were performed to evaluate complications, including pneumothorax and pulmonary haemorrhage. Factors, including the patient's position, lesion location, and pathological results, were evaluated to determine their associations with the complications. RESULTS A total of 100 patients were included, with 44 men and a mean age of 53 years old. The overall incidences of pneumothorax and pulmonary haemorrhage were 15% and 13%, respectively. The incidences of pneumothorax and pulmonary haemorrhage were statistically significantly lower in the haemocoagulase group (8% and 6%, respectively) than in the non-haemocoagulase group (22% and 20%, respectively; p=0.04 and 0.03, respectively). There was no statistically significant difference in haemoptysis between the haemocoagulase (6%) and non-haemocoagulase (2%) groups (p=0.23). There were also no statistically significant associations of pneumothorax or pulmonary haemorrhage with the patients' positions, lesion location, or pathological results. CONCLUSION Biopsy tract haemocoagulase injection reduced the incidences of postoperative pneumothorax and pulmonary haemorrhage after PTLB.
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Affiliation(s)
- S Zhou
- Department of Radiology, Chongqing General Hospital, Chongqing 400014, China
| | - F Luo
- Department of Gastroenterology, The Chongqing Traditional Chinese Medicine Hospital, Chongqing Academy of Traditional Chinese Medicine, Chongqing 400021, China
| | - M Gu
- Department of Radiology, Chongqing General Hospital, Chongqing 400014, China
| | - X Lu
- Department of Radiology, Chongqing General Hospital, Chongqing 400014, China
| | - Y Xu
- Department of Radiology, Chongqing General Hospital, Chongqing 400014, China
| | - R Wu
- Department of Radiology, Chongqing General Hospital, Chongqing 400014, China
| | - J Xiong
- Institute of Higher Education, Chongqing Medical and Pharmaceutical College, Chongqing 401334, China
| | - X Ran
- Department of Radiology, Chongqing General Hospital, Chongqing 400014, China.
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Optical and Mechanical Properties of Self-Repairing Pectin Biopolymers. Polymers (Basel) 2022; 14:polym14071345. [PMID: 35406219 PMCID: PMC9002866 DOI: 10.3390/polym14071345] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 02/06/2023] Open
Abstract
Pectin’s unique physicochemical properties have been linked to a variety of reparative and regenerative processes in nature. To investigate the effect of water on pectin repair, we used a 5 mm stainless-steel uniaxial load to fracture glass phase pectin films. The fractured gel phase films were placed on a 1.5–1.8 mm thick layer of water and incubated for 8 h at room temperature and ambient humidity. There was no immersion or agitation. The repaired pectin film was subsequently assessed for its optical and mechanical properties. Light microscopy demonstrated repair of the detectable fracture area and restoration of the films’ optical properties. The burst strength of the repaired film declined to 55% of the original film. However, its resilience was restored to 87% of the original film. Finally, a comparison of the initial and post-repair fracture patterns demonstrated no recurrent fissures in the repaired glass phase films. The water-induced repair of the pectin film was superior to the optical and mechanical properties of the repaired films composed of nanocellulose fibers, sodium hyaluronate, and oxidized cellulose. We conclude that the unique physicochemical properties of pectin facilitate the water-induced self-repair of fractured pectin films.
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Zheng Y, Pierce AF, Wagner WL, Khalil HA, Chen Z, Servais AB, Ackermann M, Mentzer SJ. Functional Adhesion of Pectin Biopolymers to the Lung Visceral Pleura. Polymers (Basel) 2021; 13:2976. [PMID: 34503016 PMCID: PMC8433721 DOI: 10.3390/polym13172976] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 01/10/2023] Open
Abstract
Pleural injuries and the associated "air leak" are the most common complications after pulmonary surgery. Air leaks are the primary reason for prolonged chest tube use and increased hospital length of stay. Pectin, a plant-derived heteropolysaccharide, has been shown to be an air-tight sealant of pulmonary air leaks. Here, we investigate the morphologic and mechanical properties of pectin adhesion to the visceral pleural surface of the lung. After the application of high-methoxyl citrus pectin films to the murine lung, we used scanning electron microscopy to demonstrate intimate binding to the lung surface. To quantitatively assess pectin adhesion to the pleural surface, we used a custom adhesion test with force, distance, and time recordings. These assays demonstrated that pectin-glycocalyceal tensile adhesive strength was greater than nanocellulose fiber films or pressure-sensitive adhesives (p < 0.001). Simultaneous videomicroscopy recordings demonstrated that pectin-glycocalyceal adhesion was also stronger than the submesothelial connective tissue as avulsed surface remnants were visualized on the separated pectin films. Finally, pleural abrasion and hyaluronidase enzyme digestion confirmed that pectin binding was dependent on the pleural glycocalyx (p < 0.001). The results indicate that high methoxyl citrus pectin is a promising sealant for the treatment of pleural lung injuries.
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Affiliation(s)
- Yifan Zheng
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.); (A.B.S.)
| | - Aidan F. Pierce
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.); (A.B.S.)
| | - Willi L. Wagner
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.); (A.B.S.)
- Department of Diagnostic and Interventional Radiology, Translational Lung Research Center, University of Heidelberg, 69120 Heidelberg, Germany
| | - Hassan A. Khalil
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.); (A.B.S.)
| | - Zi Chen
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.); (A.B.S.)
| | - Andrew B. Servais
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.); (A.B.S.)
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg-University, 55131 Mainz, Germany;
| | - Steven J. Mentzer
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.); (A.B.S.)
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Zheng Y, Pierce AF, Wagner WL, Khalil HA, Chen Z, Funaya C, Ackermann M, Mentzer SJ. Biomaterial-Assisted Anastomotic Healing: Serosal Adhesion of Pectin Films. Polymers (Basel) 2021; 13:2811. [PMID: 34451349 PMCID: PMC8401717 DOI: 10.3390/polym13162811] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/13/2021] [Accepted: 08/17/2021] [Indexed: 01/02/2023] Open
Abstract
Anastomotic leakage is a frequent complication of intestinal surgery and a major source of surgical morbidity. The timing of anastomotic failures suggests that leaks are the result of inadequate mechanical support during the vulnerable phase of wound healing. To identify a biomaterial with physical and mechanical properties appropriate for assisted anastomotic healing, we studied the adhesive properties of the plant-derived structural heteropolysaccharide called pectin. Specifically, we examined high methoxyl citrus pectin films at water contents between 17-24% for their adhesivity to ex vivo porcine small bowel serosa. In assays of tensile adhesion strength, pectin demonstrated significantly greater adhesivity to the serosa than either nanocellulose fiber (NCF) films or pressure sensitive adhesives (PSA) (p < 0.001). Similarly, in assays of shear resistance, pectin demonstrated significantly greater adhesivity to the serosa than either NCF films or PSA (p < 0.001). Finally, the pectin films were capable of effectively sealing linear enterotomies in a bowel simulacrum as well as an ex vivo bowel segment. We conclude that pectin is a biomaterial with physical and adhesive properties capable of facilitating anastomotic healing after intestinal surgery.
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Affiliation(s)
- Yifan Zheng
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.)
| | - Aidan F. Pierce
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.)
| | - Willi L. Wagner
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.)
- Department of Diagnostic and Interventional Radiology, Translational Lung Research Center, University of Heidelberg, 69117 Heidelberg, Germany
| | - Hassan A. Khalil
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.)
| | - Zi Chen
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.)
| | - Charlotta Funaya
- Electron Microscopy Core Facility, University of Heidelberg, 69117 Heidelberg, Germany;
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg-University, 55122 Mainz, Germany;
| | - Steven J. Mentzer
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (Y.Z.); (A.F.P.); (W.L.W.); (H.A.K.); (Z.C.)
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Horvath MA, Hu L, Mueller T, Hochstein J, Rosalia L, Hibbert KA, Hardin CC, Roche ET. An organosynthetic soft robotic respiratory simulator. APL Bioeng 2020; 4:026108. [PMID: 32566890 PMCID: PMC7286700 DOI: 10.1063/1.5140760] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 05/18/2020] [Indexed: 11/24/2022] Open
Abstract
In this work, we describe a benchtop model that recreates the motion and function of the diaphragm using a combination of advanced robotic and organic tissue. First, we build a high-fidelity anthropomorphic model of the diaphragm using thermoplastic and elastomeric material based on clinical imaging data. We then attach pneumatic artificial muscles to this elastomeric diaphragm, pre-programmed to move in a clinically relevant manner when pressurized. By inserting this diaphragm as the divider between two chambers in a benchtop model—one representing the thorax and the other the abdomen—and subsequently activating the diaphragm, we can recreate the pressure changes that cause lungs to inflate and deflate during regular breathing. Insertion of organic lungs in the thoracic cavity demonstrates this inflation and deflation in response to the pressures generated by our robotic diaphragm. By tailoring the input pressures and timing, we can represent different breathing motions and disease states. We instrument the model with multiple sensors to measure pressures, volumes, and flows and display these data in real-time, allowing the user to vary inputs such as the breathing rate and compliance of various components, and so they can observe and measure the downstream effect of changing these parameters. In this way, the model elucidates fundamental physiological concepts and can demonstrate pathology and the interplay of components of the respiratory system. This model will serve as an innovative and effective pedagogical tool for educating students on respiratory physiology and pathology in a user-controlled, interactive manner. It will also serve as an anatomically and physiologically accurate testbed for devices or pleural sealants that reside in the thoracic cavity, representing a vast improvement over existing models and ultimately reducing the requirement for testing these technologies in animal models. Finally, it will act as an impactful visualization tool for educating and engaging the broader community.
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Water-Dependent Blending of Pectin Films: The Mechanics of Conjoined Biopolymers. Molecules 2020; 25:molecules25092108. [PMID: 32365966 PMCID: PMC7248993 DOI: 10.3390/molecules25092108] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/01/2020] [Accepted: 04/26/2020] [Indexed: 11/17/2022] Open
Abstract
Biodegradable pectin polymers have been recommended for a variety of biomedical applications, ranging from the delivery of oral drugs to the repair of injured visceral organs. A promising approach to regulate pectin biostability is the blending of pectin films. To investigate the development of conjoined films, we examined the physical properties of high-methoxyl pectin polymer-polymer (homopolymer) interactions at the adhesive interface. Pectin polymers were tested in glass phase (10–13% w/w water content) and gel phase (38–41% w/w water content). The tensile strength of polymer-polymer adhesion was measured after variable development time and compressive force. Regardless of pretest parameters, the adhesive strength of two glass phase films was negligible. In contrast, adhesion testing of two gel phase films resulted in significant tensile adhesion strength (p < 0.01). Adhesion was also observed between glass phase and gel phase films—likely reflecting the diffusion of water from the gel phase to the glass phase films. In studies of the interaction between two gel phase films, the polymer-polymer adhesive strength increased linearly with increasing compressive force (range 10–80 N) (R2 = 0.956). In contrast, adhesive strength increased logarithmically with time (range 10–10,000 s) (R2 = 0.913); most of the adhesive strength was observed within minutes of contact. Fracture mechanics demonstrated that the adhesion of two gel phase films resulted in a conjoined film with distinctive physical properties including increased extensibility, decreased stiffness and a 30% increase in the work of cohesion relative to native polymers (p < 0.01). Scanning electron microscopy of the conjoined films demonstrated cross-grain adhesion at the interface between the adhesive homopolymers. These structural and functional data suggest that blended pectin films have emergent physical properties resulting from the cross-grain intermingling of interfacial pectin chains.
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Pierce A, Zheng Y, Wagner WL, Scheller HV, Mohnen D, Tsuda A, Ackermann M, Mentzer SJ. Pectin biopolymer mechanics and microstructure associated with polysaccharide phase transitions. J Biomed Mater Res A 2020; 108:246-253. [PMID: 31595695 PMCID: PMC7238754 DOI: 10.1002/jbm.a.36811] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 09/11/2019] [Accepted: 09/16/2019] [Indexed: 01/01/2023]
Abstract
Polysaccharide polymers like pectin can demonstrate striking and reversible changes in their physical properties depending upon relatively small changes in water content. Recent interest in using pectin polysaccharides as mesothelial sealants suggests that water content, rather than nonphysiologic changes in temperature, may be a practical approach to optimize the physical properties of the pectin biopolymers. Here, we used humidified environments to manipulate the water content of dispersed solution of pectins with a high degree of methyl esterification (high-methoxyl pectin; HMP). The gel phase transition was identified by a nonlinear increase in compression resistance at a water content of 50% (w/w). The gel phase was associated with a punched-out fracture pattern and scanning electron microscopy (SEM) images that revealed a cribiform (Swiss cheese-like) pectin microstructure. The glass phase transition was identified by a marked increase in resilience and stiffness. The glass phase was associated with a star-burst fracture pattern and SEM images that demonstrated a homogeneous pectin microstructure. In contrast, the burst strength of the pectin films was largely independent of water content over a range from 5 to 30% (w/w). These observations indicate the potential to use water content in the selective regulation of the physical properties of HMP biopolymers.
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Affiliation(s)
- Aidan Pierce
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston MA
| | - Yifan Zheng
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston MA
| | - Willi L. Wagner
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston MA
- Department of Diagnostic and Interventional Radiology, Translational Lung Research Center, University of Heidelberg, Heidelberg, Germany
| | - Henrik V. Scheller
- Joint BioEnergy Institute, Emeryville CA and the Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Debra Mohnen
- Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA
| | - Akira Tsuda
- Molecular and Integrative Physiological Sciences, Harvard School of Public Health, Boston, MA
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Steven J. Mentzer
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston MA
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Zheng Y, Pierce A, Wagner WL, Scheller HV, Mohnen D, Tsuda A, Ackermann M, Mentzer SJ. Analysis of pectin biopolymer phase states using acoustic emissions. Carbohydr Polym 2020; 227:115282. [PMID: 31590860 PMCID: PMC6936603 DOI: 10.1016/j.carbpol.2019.115282] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 08/10/2019] [Accepted: 08/31/2019] [Indexed: 11/28/2022]
Abstract
Acoustic emissions are stress or elastic waves produced by a material under external load. Since acoustic emissions are generated from within and transmitted through the substance, the acoustic signature provides insights into the physical and mechanical properties of the material. In this report, we used a constant velocity probe with force and acoustic emission monitoring to investigate the properties of glass phase and gel phase pectin films. In the gel phase films, a constant velocity uniaxial load produced periodic premonitory acoustic emissions with coincident force variations (saw-tooth pattern). SEM images of the gel phase microarchitecture indicated the presence of slip planes. In contrast, the glass phase films demonstrated early acoustic emissions, but effectively no force or acoustic evidence of periodic or premonitory emissions. Microstructural imaging of the glass phase films indicated the presence of early microcracks as well as dense polymerization of the pectin (without evidence of slip planes). We conclude that the water content in the pectin films contributes to not only the physical properties of the films, but also the stick-slip motion observed with constant uniaxial load. Further, acoustic emissions provide a sensitive and practical measure of this mechanical behavior.
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Affiliation(s)
- Yifan Zheng
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Aidan Pierce
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Willi L Wagner
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, United States; Department of Diagnostic and Interventional Radiology, Translational Lung Research Center, Univeristy of Heidelberg, Heidelberg, Germany
| | - Henrik V Scheller
- Joint BioEnergy Institute, Emeryville CA and the Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Debra Mohnen
- Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Akira Tsuda
- Molecular and Integrative Physiological Sciences, Harvard School of Public Health, Boston, MA, United States
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Steven J Mentzer
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, United States.
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Byun C, Zheng Y, Pierce A, Wagner WL, Scheller HV, Mohnen D, Ackermann M, Mentzer SJ. The Effect of Calcium on the Cohesive Strength and Flexural Properties of Low-Methoxyl Pectin Biopolymers. Molecules 2019; 25:E75. [PMID: 31878302 PMCID: PMC6982731 DOI: 10.3390/molecules25010075] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/13/2019] [Accepted: 12/18/2019] [Indexed: 11/23/2022] Open
Abstract
Abstract: Pectin binds the mesothelial glycocalyx of visceral organs, suggesting its potential role as a mesothelial sealant. To assess the mechanical properties of pectin films, we compared pectin films with a less than 50% degree of methyl esterification (low-methoxyl pectin, LMP) to films with greater than 50% methyl esterification (high-methoxyl pectin, HMP). LMP and HMP polymers were prepared by step-wise dissolution and high-shear mixing. Both LMP and HMP films demonstrated a comparable clear appearance. Fracture mechanics demonstrated that the LMP films had a lower burst strength than HMP films at a variety of calcium concentrations and hydration states. The water content also influenced the extensibility of the LMP films with increased extensibility (probe distance) with an increasing water content. Similar to the burst strength, the extensibility of the LMP films was less than that of HMP films. Flexural properties, demonstrated with the 3-point bend test, showed that the force required to displace the LMP films increased with an increased calcium concentration (p < 0.01). Toughness, here reflecting deformability (ductility), was variable, but increased with an increased calcium concentration. Similarly, titrations of calcium concentrations demonstrated LMP films with a decreased cohesive strength and increased stiffness. We conclude that LMP films, particularly with the addition of calcium up to 10 mM concentrations, demonstrate lower strength and toughness than comparable HMP films. These physical properties suggest that HMP has superior physical properties to LMP for selected biomedical applications.
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Affiliation(s)
- Christine Byun
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (C.B.); (Y.Z.); (A.P.); (W.L.W.)
| | - Yifan Zheng
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (C.B.); (Y.Z.); (A.P.); (W.L.W.)
| | - Aidan Pierce
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (C.B.); (Y.Z.); (A.P.); (W.L.W.)
| | - Willi L. Wagner
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (C.B.); (Y.Z.); (A.P.); (W.L.W.)
- Department of Diagnostic and Interventional Radiology, Translational Lung Research Center, University of Heidelberg, 69115 Heidelberg, Germany
| | - Henrik V. Scheller
- Joint BioEnergy Institute, Emeryville CA and the Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94701, USA;
| | - Debra Mohnen
- Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA;
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg-University Mainz, 55131 Mainz, Germany;
| | - Steven J. Mentzer
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (C.B.); (Y.Z.); (A.P.); (W.L.W.)
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