Polypropylene in ophthalmology: biomechanical properties, Degradation, and clinical use of monofilament fibers | Markéta Debnarová
Polypropylene in Ophthalmology
Authors: Markéta Debnarová (1), Veronika Hátlová (2), Věra Křížková (3), Lenka Vaňková (3), Jan
Cendelín (4), Hecová L. (1), Štěpán Rusňák (1), Pavel Studený (2)
Supervisor: Štěpán Rusňák (1)
(1) Department of Ophthmalmology, Faculty of Medicine in Pilsen, Charles University and Uni
versity Hospital, Pilsen (2) Department of Histology and Embryology, Faculty of Medicine in
Pilsen, Charles University (3) Department of Pathology, Faculty of Medicine in Pilsen, Charles
University and University Hospital, Pilsen(4) Department of Pathological Physiology, Faculty of
Medicine in Pilsen, Charles University
State-of-the-Art: Polypropylene is one of the most widely used synthetic suture materials in
surgery. In ophthalmology it plays an important role in microsurgical procedures requiring sta
ble and biologically well-tolerated materials. Due to its chemical stability, low tissue reactivity
and favorable mechanical properties, polypropylene has become a standard material. Despite
its long clinical use, increasing attention has recently been paid to the biomechanical properties
of polypropylene sutures and their long-term behavior in ocular tissues.
Objective: The aim of this work is to summarize current knowledge on the biomechanical prop
erties, biocompatibility and degradation of polypropylene sutures used in ophthalmology, with
particular focus on their role in scleral fixation of intraocular lenses.
Material and Methods: This work is based on a review of current scientific literature focusing
on the use of polypropylene sutures in ophthalmology. In addition, ongoing experimental re
search investigating tissue reactions to different scleral suspension materials in an in vivo rabbit
model was considered. Histological analysis of scleral tissue was used to evaluate inflammatory
response and collagen formation around implanted fibers.
Results & Discussion: Available experimental and clinical studies indicate that polypropylene
sutures are generally well tolerated by ocular tissues and provide stable fixation of intraocular
implants. However, long-term implantation may lead to gradual structural changes of the poly
mer fiber, including surface microcracks and mechanical weakening, which in some cases may
result in late suture breakage and implant dislocation. These findings have led to modifications
in surgical techniques and to the use of thicker polypropylene sutures in order to increase me
chanical stability. Modern fixation techniques and modified suture configurations may improve
long-term clinical outcomes.
Conclusion: Polypropylene remains an important suture material in ophthalmic surgery due to
its chemical stability, favorable mechanical properties and good tissue tolerance. However, the
optimal suture diameter and surgical technique for long-term implantation have not yet been
clearly defined.
Funding: Supported by the Cooperatio program, research areas MED/DIAG and Surgical Disci
plines.
Biological augmentation of different types of meniscus repair using fibrin clot | Jan Zeman
Fibrin clot in meniscus repair
Authors: Jan Zeman (1), Petr Zeman (1), Štěpán Vlček (1)
Supervisor: Petr Zeman (1)
(1) Department of Orthopaedics and Locomotive Apparatus Traumatology, Faculty of Medicine
in Pilsen, Charles University and University Hospital, Pilsen
State-of-the-Art: Menisci are essential structures of the knee joint and are crucial for prop
er knee function and biomechanics. Degenerative lesions and traumatic ruptures are found in
almost every patient who undergoes knee arthroscopy, and in recent years there has been a
significant shift toward meniscal preservation, particularly in younger patients, rather than per
forming a simple meniscectomy. However, some of these lesions are difficult to repair and have
limited healing potential, mainly due to the poor blood supply in certain regions of the menisci.
Therefore, biological augmentation is often required to ensure a satisfactory clinical outcome;
however, many of these methods are expensive or not readily available to all patients.
Objective: To evaluate the clinical effectiveness of autologous fibrin clot augmentation in me
niscal repair.
Material and Methods: In our department, we frequently use a fibrin clot to augment meniscal
repairs. This is a safe and inexpensive method in which a fibrin clot is prepared directly from
the patient’s venous blood and then applied into the meniscal lesion together with the suture.
The fibrin clot serves as a source of important growth factors such as PDGF, TGF-β, and VEGF. It
also acts as a natural scaffold for fibroblasts or mesenchymal stem cells and, due to its adhesive
properties, functions as a biological glue. Our indications mainly include complex meniscal tears
such as bucket-handle tears, horizontal cleavage lesions, and radial ruptures.
Results & Discussion: We are conducting a prospective clinical study involving patients with
various types of meniscal lesions who underwent meniscal suturing with or without augmen
tation using an autologous fibrin clot. The aim of the study is to evaluate the effect of fibrin
clot augmentation on the healing of sutured menisci. We monitor the occurrence of repair fail
ure, the need for reoperation, and other complications. IKDC and Lysholm scores are assessed,
and follow-up MRI examinations are performed. Patients treated with fibrin clot augmentation
demonstrated a statistically significant improvement in postoperative IKDC and Lysholm scores,
along with a reduced rate of suture failure compared to non-augmented repairs.
Conclusion: Autologous fibrin clot augmentation is a safe, inexpensive, and effective method to
enhance healing in meniscal repairs, particularly in complex tear patterns
regeneration of extrahepatic bile ducts after their reconstruction and its differences -experiment on large animal model | Jan Ševčík
Differences in bile duct regeneration
Authors: Jan Ševčík (1,2), Maria Stefania Massaro (2), Lenka Červenková (2), Grajcarová Martina (3),
Ekaterina Panova (2), Sima Šarčevič (1,2), Richard Pálek (1,2), Ilya Matsviayonak (1,2), Petr Hošek (2),
Vladimíra Moulisová (2)
Supervisor: Václav Liška (1,2)
(1) Department of Surgery, Faculty of Medicine in Pilsen, Charles University and University Hos
pital, Pilsen (2) Biomedical Center, Faculty of Medicine in Pilsen, Charles University (3) Depart
ment of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University
State-of-the-Art: Despite todays age biliary surgery still poses a significant challenge even for
experienced HPB surgeons. It‘s complexity lies in combination of technicaly challenging proce
dures paired with its long term complications, especialy tendencies to form stenosis in site of
biliary reconstruction with subsequent biliary obstruction, weighing patients with additive mor
bidity. Current understanding behind the processes leading to this situations is limited, which
complicates further research seeking possible solutions. Due to theese facts we decided to com
pare healing of bile duct reconstructed by a) direct anastomosis, b) decelularized interponate
after 4 weeks with native bile duct on domestic pig model.
Objective: To do a clinical and histological comparison of bile duct healing after different meth
ods of extrahepatic bile duct reconstruction with native bile duct with intention to identify pos
sible processes leading to stenosis formation.
Material and Methods: Porcine extrahepatic bile duct grafts were harvested under sterile con
ditions, than divided into 2 subgroups – a) native bile ducts for comparison b) bile ducts used for
decelularized graft procurement.First experimental group (N = 7) of pigs underwent resection of
a segment of the common bile duct, followed by anatomical reconstruction using an interposed
decellularized graft. Second experimental group (N = 6) underwent direct anatomical recon
struction without an interposition graft. The comparison aimed to evaluate clinical, qualitative
and quantitative histological diferences after 4 weeks of healing in recipients body with native
bile duct characteristics.
Results & Discussion: No statistically significant differences were observed between the exper
imental and control groups in overall survival, morbidity, mortality, or complication rates. The
experimental group showed a slight, statistically insignificant increase in alkaline phosphatase
levels, without elevation of other markers of biliary obstruction, suggesting no relevant impair
ment of biliary function. Histological analysis revealed higher presence of inflammatory cells in
the muscular layer of the group reconstructed by decelularized graft. A higher collagen I/III ratio
in the same group may indicate ongoing graft remodeling. Lower smooth muscle actin expres
sion in the serosa of likely reflects reduced peritoneal surface contact due to graft interposition.
Conclusion: Level of epithelial coverage integrity of the reconstructed part coupled with suc
cesfull peritoneal sheets interraction may affect the healing process of bile duct recosntruction.
Further study with cross-sections across individual time periods is required.
Funding: The study was supported by GA UK grant No. 434522 (Charles University) and Cooper
atio project “Surgical disciplines” (COOPERATIO-207043, Charles University).
Prevention of esophageal anastomotic leak using a nanofibrous mmp-9-inhibiting patch: a large animal experimental study | Sima Šarčević
Patch preventing esophageal anastomotic leaks
Authors: Sima Šarčević (1,2), Richard Pálek (1,2), Jáchym Rosendorf (1,2), Jan Ševčík (1,2), Lenka Čer
venková (2), Vladimíra Moulisová (2), Ekaterina Panova (2), Daniel Lehner (2), Markéta Klíčová (3),
Jana Horáková (3)
Supervisor: Václav Liška (1,2)
(1) Department of Surgery, Faculty of Medicine in Pilsen, Charles University and Universi
ty Hospital, Pilsen (2) Biomedical Center, Faculty of Medicine in Pilsen, Charles University
(3) Department of Nonwovens and Nanofibrous Materials, Faculty of Textile Engineering, Tech
nical University of Liberec
State-of-the-Art: Surgical resection remains the only curative treatment for esophageal car
cinoma. Esophageal anastomotic leak is a serious postoperative complication, occurring in
10–20% of cases. Despite advances in surgical techniques, perioperative care, and minimally
invasive approaches, its incidence has not significantly decreased. Indicators of anastomotic
healing include collagen content and mechanical strength. Experimental studies have shown
that systemic inhibition of matrix metalloproteinase-9 (MMP-9) can increase collagen propor
tion in the anastomosis and improve its mechanical strength. In the past, our team successfully
developed nanofibrous patches supporting gastrointestinal anastomotic healing. A new plat
form incorporating an MMP-9 inhibitor is being tested to prevent esophageal leaks.
Objective: To evaluate the feasibility and potential protective effect of a polycaprolactone na
nofibrous patch containing an MMP-9 inhibitor on the healing of esophageal anastomosis in a
large animal experimental model.
Material and Methods: The experiment included 24 pigs divided into four groups of six: (1)
control, 1-week survival; (2) control, 3-week survival; (3) experimental, 1-week survival; and (4)
experimental, 3-week survival. Control animals underwent standard esophageal reconstruc
tion. In the experimental groups, a nanofibrous patch containing the MMP-9 inhibitor JNJ-0966
(MedChemExpress, USA) was applied around the anastomosis. The two observation periods
were chosen to evaluate anastomotic healing during the inflammatory, proliferative, and re
modeling phases. Clinical status was monitored daily. Laboratory tests and CT examinations
were performed preoperatively and on postoperative days 3, 7, 14, and 21. After euthanasia,
tissue samples were collected for macroscopic, histological, RNA, and protein analyses.
Results & Discussion: The experimental model of esophageal reconstruction in pigs using a
nanofibrous patch was successfully established despite technical difficulties during patch ap
plication due to limited esophageal mobility. The postoperative course was largely uneventful.
Animals tolerated soft oral intake from postoperative day 2. CT scans revealed no clinically signif
icant esophageal anastomotic leak. Macroscopic evaluation identified three minor anastomotic
dehiscences (12.5%) with localized abscess formation. The incidence of defects appeared lower
in animals with the patch than in controls. Histological examination showed incomplete healing
in all animals, with a purulent inflammatory infiltrate in the submucosa and suture area. The
patch was not completely absorbed after three weeks.
Conclusion: Application of a nanofibrous patch containing the MMP-9 inhibitor appears fea
sible and may reduce minor anastomotic defects. More detailed microscopic and molecular
analyses are ongoing (e.g., MMP-9 gene expression and protein activity) to further elucidate the
protective effect of the patch
Funding: Funded by Charles University Grant Agency (GAUK), project No. 204324: “Prevention
of esophageal anastomotic leak using an innovative nanofibrous material inhibiting MMP-9 ac
tivity in a large animal model