Fatty-acid-derived ester-urethane macromonomers synthesized using bismuth and zinc catalysts

Minimally invasive surgical approaches require the development of new injectable materials. A particularly attractive strategy involves using photocurable materials that can be delivered as liquids and rapidly cured in situ using UV light. The aim of this work was to synthesize and characterize fatty-acid-derived ester-urethane telechelic (methacrylate) macromonomers, suitable for photopolymerization. The commonly used dibutyltin dilaurate catalyst was replaced with bismuth neodecanoate, bismuth tris(2-ethylhexanoate), and zinc (II) acetyloacetonate as less-toxic alternative catalysts. Additionally, ethyl acetate was used as a “green” solvent. The progress of the two-step synthesis was monitored with infrared spectroscopy. The chemical structure and molecular weight of the obtained viscous materials was characterized with nuclear magnetic resonance spectroscopy and gel permeation chromatography. Photocrosslinking of the macromonomers into elastomeric films was achieved using 150 s per spot of UV light (20 mW/cm2) exposure. Mechanical tensile testing of the films confirmed tensile strength and modulus values in a range of values typical of soft tissue. Finally, in vitro cytotoxicity tests showed high cell viability for the case of materials synthesized using bismuth and zinc catalysts. Overall, our results indicate that bismuth and zinc catalysts are excellent alternatives to organotin compounds in the synthesis of photocurable methacrylate ester-urethanes for biomedical applications, such as minimally invasive surgical protocols.

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Fatty-acid-derived ester-urethane macromonomers synthesized using bismuth and zinc catalysts

10.33774/chemrxiv-2021-cr10g-v2 ◽

2022 ◽

Author(s):

Malwina Niedzwiedz ◽

Gokhan Demirci ◽

Nina Kantor-Malujdy ◽

Peter Sobolewski ◽

Miroslawa El Fray

Keyword(s):

Fatty Acid ◽

Uv Light ◽

Gel Permeation Chromatography ◽

In Vitro Cytotoxicity ◽

Dibutyltin Dilaurate ◽

Resonance Spectroscopy ◽

Elastomeric Materials ◽

Low Modulus ◽

Mechanical Tensile

Photocurable materials that can be delivered as liquids and rapidly (within seconds) cured in situ using UV light are gaining increased interest in advanced minimally invasive procedures. The aim of this work was to synthesize and characterize fatty-acid-derived ester-urethane telechelic (methacrylate) macromonomers, suitable for photopolymerization. The commonly used dibutyltin dilaurate catalyst was replaced with bismuth neodecanoate, bismuth tris(2-ethylhexanoate), and zinc (II) acetyloacetonate as less-toxic alternative catalysts. Additionally, ethyl acetate was used as a “green” solvent. The progress of the two-step synthesis was monitored with infrared spectroscopy. The chemical structure and molecular weight of the obtained viscous materials was characterized with nuclear magnetic resonance spectroscopy and gel permeation chromatography. Photocrosslinking of the macromonomers into elastomeric films was achieved using 150 s per spot of UV light (20 mW/cm2) exposure. Mechanical tensile testing of the films indicated their elasticity up to 120% and low modulus typical for soft and elastomeric materials. Finally, in vitro cytotoxicity tests showed high cell viability for the case of materials synthesized using bismuth and zinc catalysts. Overall, our results indicate that bismuth and zinc catalysts are excellent alternatives to organotin compounds in the synthesis of photocurable methacrylate ester-urethanes for potential biomedical applications.

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Minimally Invasive Surgical Approaches to Kidney Stones in Children

Current Urology Reports ◽

10.1007/s11934-012-0259-8 ◽

2012 ◽

Vol 13 (4) ◽

pp. 298-306 ◽

Cited By ~ 9

Author(s):

Hasan Serkan Dogan ◽

Serdar Tekgul

Keyword(s):

Minimally Invasive ◽

Kidney Stones ◽

Surgical Approaches ◽

Minimally Invasive Surgical

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Minimally Invasive Surgical Approaches to Colon Cancer

Surgical Oncology Clinics of North America ◽

10.1016/j.soc.2017.11.005 ◽

2018 ◽

Vol 27 (2) ◽

pp. 303-318 ◽

Cited By ~ 7

Author(s):

Jean F. Salem ◽

Sriharsha Gummadi ◽

John H. Marks

Keyword(s):

Colon Cancer ◽

Minimally Invasive ◽

Surgical Approaches ◽

Minimally Invasive Surgical

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Minimally Invasive Resection of Benign Gastric Tumors in Challenging Locations: Prepyloric Region or Gastroesophageal Junction

The American Surgeon ◽

10.1177/000313481307901002 ◽

2013 ◽

Vol 79 (10) ◽

pp. 968-972 ◽

Cited By ~ 1

Author(s):

Christopher Armstrong ◽

Alana Gebhart ◽

Brian R. Smith ◽

Ninh T. Nguyen

Keyword(s):

Minimally Invasive ◽

Perioperative Complications ◽

Wedge Resection ◽

Gastroesophageal Junction ◽

Surgical Techniques ◽

Surgical Approaches ◽

Anatomic Resection ◽

Submucosal Tumors ◽

Gastric Tumors ◽

Minimally Invasive Surgical

Benign gastric tumors in a prepyloric location or within 3 cm adjacent of the gastroesophageal junction (GEJ) are often challenging to resect using minimally invasive surgical techniques. The aim of this study was to examine the outcomes of patients who underwent minimally invasive enucleation or resection of benign gastric tumors at these difficult locations. The charts of patients undergoing minimally invasive resection of benign-appearing submucosal gastric tumors between June 2001 and December 2012 were reviewed. Data on tumor size and location, type of minimally invasive surgical resection, perioperative complications, 90-day mortality, pathology, and recurrence were collected. A total of 70 consecutive patients underwent laparoscopic resection of benign-appearing submucosal gastric tumors; there were 24 patients with lesions close to the GEJ and nine patients with lesions close to the prepyloric region. All lesions were successfully resected laparoscopically. For prepyloric tumors, surgical approaches included enucleation (n = 1), wedge resection (n = 2), and distal gastrectomy with reconstruction (n = 6). For tumors close to the GEJ, surgical approaches included enucleation (n = 16), wedge resection (n = 3), and esophagogastrectomy (n = 5). Complications in this series of 33 patients included late strictures requiring endoscopic dilation in three patients who underwent esophagogastrectomy. The 90-day mortality rate was zero. There were no recurrences over a mean follow-up of 15 months (range, 1 to 86 months). Minimally invasive enucleation or formal anatomic resection of submucosal tumors located adjacent to the GEJ or at the prepyloric region is safe and carries a low risk for tumor recurrence. Submucosal gastric lesions adjacent to the GEJ are amenable to laparoscopic enucleation or wedge resection unless they extend proximally into the esophagus. Prepyloric lesions often require formal anatomic resection with reconstruction.

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