Dura Mater Defects Research Articles

A robust and biodegradable hydroxyapatite/poly(lactide-co-ε-caprolactone) electrospun membrane for dura repair.

Typically occurring after trauma or neurosurgery treatments, dura mater defect and the ensuing cerebrospinal fluid (CSF) leakage could lead to a number of serious complications and even patient's death. Although numerous natural and synthetic dura mater substitutes have been reported, none of them have been able to fulfill the essential properties, such as anti-adhesion, leakage blockage, and pro-dura rebuilding. In this study, we devised and prepared a series of robust and biodegradable hydroxyapatite/poly(lactide-co-ε-caprolactone) (nHA/PLCL) membranes for dura repair via an electrospinning technique. In particular, PLLA/PCL (80/20) was selected for electrospinning due to its mechanical properties that most closely resembled natural dural tissue. Studies by SEM, XRD, water contact angle and in vitro degradation showed that the introduction of nHA would destroy PLCL's crystalline structure, which would further affect the mechanical properties of the nHA/PLCL membranes. When the amount of nHA added increased, so did the wettability and in vitro degradation rate, which accelerated the release of nHA. In addition, the high biocompatibility of nHA/PLCL membranes was demonstrated by in vitro cytotoxicity data. The in vivo rabbit dura repair model results showed that nHA/PLCL membranes provided a strong physical barrier to stop tissue adhesion at dura defects. Meanwhile, the nHA/PLCL and commercial group's CSF had a significantly lower number of inflammatory cells than the control groups, validating the nHA/PLCL's ability to effectively lower the risk of intracranial infection. Findings from H&E and Masson-trichrome staining verified that the nHA/PLCL electrospun membrane was more favorable for fostering dural defect repair and skull regeneration. Moreover, the relative molecular weight of PLCL declined dramatically after 3 months of implantation, according to the results of the in vivo degradation test, but it retained the fiber network structure and promoted tissue growth, demonstrating the good stability of the nHA/PLCL membranes. Collectively, the nHA/PLCL electrospun membrane presents itself as a viable option for dura repair.

Using lyophilized bovine pericardium and acellular ovine esophageal mucosa to repair cerebral dura mater defect in dogs

Using lyophilized bovine pericardium and acellular ovine esophageal mucosa to repair cerebral dura mater defect in dogs

Repair of the cerebral dura mater defect by temporalis muscle fascia or peritoneum as autografted tissues in dogs

Repair of the cerebral dura mater defect by temporalis muscle fascia or peritoneum as autografted tissues in dogs

Differences in invasiveness and recurrence rate among nonfunctioning pituitary neuroendocrine tumors depending on tumor subtype.

To clarify the invasiveness to surrounding structures and recurrence rate of each subtype of nonfunctioning pituitary neuroendocrine tumor (Pit-NETs) according to the WHO 2022 classification. This retrospective study utilized data from 292 patients with nonfunctioning Pit-NETs treated with initial transsphenoidal surgery. Recurrence was evaluated on 113 patients who were available for a magnetic resonance imaging follow-up ≥ 60months. All tumors were assessed by immunohistochemical staining for Pit-1, T-PIT, and GATA3. Invasiveness to surrounding structures was evaluated based on intraoperative findings. Cavernous sinus invasion was found in 47.5% of null cell tumors, 50.0% of Pit-1 lineage tumors, 31.8% of corticotroph tumors, and 18.3% of gonadotroph tumors. Dura mater defects in the floor of sellar turcica, indicating dural invasion, were found in 44.3% of null cell tumors, 36.4% of corticotroph tumors, 16.7% of Pit-1 lineage tumors, and 17.3% of gonadotroph tumors. In logistic regression analysis, Pit-1 (OR 5.90, 95% CI 1.71-20.4, P = 0.0050) and null tumors (OR 4.14, 95% CI 1.86-9.23, P = 0.0005) were associated with cavernous sinus invasion. Recurrence was found in 8 (4.9%) patients, but without significant differences between tumor subtypes. The presence of cavernous sinus invasion was correlated with recurrence (HR = 1.95, 95% CI 1.10-3.46, P = 0.0227). Among nonfunctioning Pit-NETs, Pit-1 lineage tumors tend to invade the cavernous sinus, corticotroph tumors may produce dura mater defects, and null cell tumors tend to cause both. Pit-NETs with cavernous sinus invasion require a careful attention to recurrence.

Dural Reconstruction Materials for the Repairing of Spinal Neoplastic Cerebrospinal Fluid Leaks.

Spinal tumors often lead to more complex complications than other bone tumors. Nerve injuries, dura mater defect, and subsequent cerebrospinal fluid (CSF) leakage generally appear in spinal tumor surgeries and are followed by serious adverse outcomes such as infections and even death. The use of suitable dura mater replacements to achieve multifunctionality in fluid leakage plugging, preventing adhesions, and dural reconstruction is a promising therapeutic approach. Although there have been innovative endeavors to manage dura mater defects, only a handful of materials have realized the targeted multifunctionality. Here, we review recent advances in dura repair materials and techniques and discuss the relative merits in both preclinical and clinical trials as well as future therapeutic options. With these advances, spinal tumor patients with dura mater defects may be able to benefit from novel treatments.

Bipolar high-frequency electric welding in radical resection of frontal sinus tumors.

The aim of study is to develop a new method of connecting the dura mater (DM) defects in frontal sinus tumors with intracranial spread using high-frequency bipolar coagulation for welding of living tissues. Depending on the method of DM defect repair, patients were divided into two groups. The 1st group (control) included patients whose DM defect was connected according to the conventional method (suturing with polypropylene threads), in the 2nd group-the DM defect was connected by high-frequency bipolar electric welding using EKVZ-300, Patonmed. As a result of the study, the authors proposed an effective method of connecting the DM defects after the removal of frontal sinus tumors spreading intracranially. Such methods include a high-frequency bipolar electric welding method, the use of which contributed to a minimal destructive effect on adjacent tissues, but at the same time hermetically connected the DM. This was possible due to the supply of current with certain wave characteristics in a certain modulation at a temperature of 40-48°C, resulting in the connection of tissues without the formation of a coagulation scab due to the mechanism of protein-associated electrothermal adhesion of tissues. Presented data indicate significant advantages of using high-frequency bipolar electric welding the DM defects and fascia lata to restore the closed physiological circuit of cerebrospinal fluid circulation, compared to the traditional suture method. This approach has reduced intra- and post-operative complications, the time of surgery, and the length of the postoperative period.

The Results of Using the Method of Bipolar High-frequency Electric Welding to Close Defects of the Dura Mater in Frontal Sinus Tumors with Intracranial Spread, and its Comparison with the Standard Method

The frequency of cerebrospinal fluid leak (CSFL) in the postoperative period after surgical interventions on the structures of the skull base reaches 6.2%, and after interventions on the structures of the anterior cranial fossa - 5.9%, middle cranial fossa - 6.4% and - 5.8% in all subtentorial interventions (Jamshidi, 2022; Rajendran, 2020). The aim of the study is to increase the effectiveness of surgical treatment of patients with tumors of the frontal sinuses with intracranial spread by using the method of high-frequency bipolar electric welding. Depending on the method of dura mater defect repair, patients were divided into 2 groups. The 1st group (control) included patients whose dura mater defect was connected according to the conventional method (suturing with polypropylene threads). In the 2nd group – the dura mater defect was connected by high-frequency bipolar electric welding. Patients of the 1st and 2nd groups were divided into 2 subgroups. Subgroups 1A and 2A included patients in whom the DM defect was up to 3 cm in diameter and linear; if necessary, a pericranium was used to close the DM defect. Subgroups 1B and 2B included patients in whom the connection of the defect was performed with the help of a fascia lata. As a result of the study, the authors proposed an effective method of connecting the dura mater defects after the removal of frontal sinus tumors spreading intracranially. Such methods include a high-frequency bipolar electric welding method, the use of which contributed to a minimal destructive effect on adjacent tissues but at the same time hermetically connected the dura mater. Presented data indicate that the use of high-frequency bipolar electric welding allowed to reduce the frequency of external CSFL by 2.2 times, compared to the use of suture material, and to reduce of hidden CSFL by 4.6 times, which indicates a statistically significant advantage of using high-frequency bipolar electric welding to close DM defects and prevent the occurrence of external and hidden CSFL in the postoperative period. In the presence of a DM defect of more than 3 cm and when it is closed with the fascia lata, it is possible to reduce the occurrence of external CSFL by 2.0 times compared to the control group. The use of high-frequency bipolar electric welding almost completely reduces the possibility of the formation of a meningeal scar in the postoperative period, which significantly accelerates the recovery of CSFL circulation and the recovery of brain tissue (due to the absence of factors that would irritate it), as a result of which the patient's rehabilitation and recovery are faster, compared to standard methods of connecting DM. The use of high-frequency bipolar electric welding was manifested by a faster recovery of normal intracranial pressure indicators - a faster recovery of fluid dynamics, a faster regression of inflammatory changes in the brain tissue and, as a result, a faster recovery of its functions, which indicates a higher quality of life of postoperative patients in the main group, compared to the control group.

Research Progress of Rigid Skull Base Reconstruction after Transnasal Endoscopy

With the rapid development of diagnosis and treatment technology, equipment and instruments in the new era of neurosurgery, [1, 2] endoscope-assisted transnasal skull base surgery technology is becoming increasingly mature, surgical indications show an expanding trend, and the types of treated lesions are increasing day by day under the advantages of less trauma, quick recovery, high total resection rate and clear visual field exposure [3-5]. However, cerebrospinal fluid leakage and severe intracranial infection caused by the defect of skull base bone and dura mater have a great adverse impact on the prognosis of patients. Therefore, how to carry out long-lasting and effective skull base reconstruction after successful tumor resection is particularly important to reduce the occurrence of cerebrospinal fluid leakage after operation. Currently, there is no uniform standard for skull base reconstruction methods, which can be roughly divided into soft reconstruction and rigid reconstruction [6, 7]. There is no doubt about the importance of soft reconstruction in tissue water sealing, but rigid reconstruction of skull base is often ignored or even controversial [6]. In this paper, various techniques of skull base rigid reconstruction are reviewed, and the necessity of skull base rigid reconstruction is expounded.

Collagen-Based Grafts and Autologous Dura Replacement in Patients with Dura Abnormalities: A Retrospective Comparative Evaluation

Introduction: Accidental spinal anomalies of the spinal dura mater are the source of cerebrospinal fluid (CSF) leakage. Typically, dura abnormalities are identified in 3 percent of endoscopic lumbar discectomy cases. Objective: The purpose of the current research was to evaluate the results of autologous dura replacement versus collagen-based grafts in individuals with dura deformities. Methods: The Institute of Neurosurgery at Liaquat National Hospital Karachi undertook this randomized evaluation to identify the most effective therapy for dura mater defects. Employing non-probability random selection, 82 cases among both sexes were selected. Participants were divided randomly into two subgroups i.e. Group 1A received an autologous graft for dura restoration, whereas Group 2B received a semi-synthetic dura replacement. A skilled surgeon led a medical team of six people who completed the entire process. Results: The operation duration for semi-synthetic collagen was significantly reduced. There was a 40 minute variation in total time spent by the two groups. Autologous grafts showed ideal tightness and better flexibility and fair workability on the other hand semi-synthetic collagen showed better tightness and workability and ideal flexibility. Postoperative hospital stays were seen to be 26 + 2.5 hours in Group 1A whereas they were 23 + 2.5 hours for Group B. Conclusion: According to the aforementioned findings, an accessible, secure, and efficient substitution for an autologous graft for dura restoration in dura abnormalities is the use of a semi-synthetic collagen substitute. Keywords: semi-synthetic collagen substitute, cerebrospinal fluid, dura abnormalities, autologous graft.

Surgical treatment of epidural arachnoid cyst type II of the thoracic and lumbar spine: case report

Background. Spinal epidural arachnoid cysts are the protrusion of the arachnoid membrane through an existing defect in the dural, functioning as a valve. Literature data on diagnosis and surgical treatment are presented by descriptions of clinical cases and there is no consensus on the optimal approach to solving this problem.Aim. To present a clinical case of surgical treatment of epidural arachnoid cyst type II of the thoracic and lumbar spine; to analyze methods of diagnosis and surgical treatment of such cysts.Materials and methods. All cases of diagnosis and treatment of spinal epidural arachnoid cysts in adults published in the PubMed search engine by 2021 have been analyzed. A clinical case of successful surgical treatment of an epidural arachnoid cyst of the thoracic and lumbar spine of type II on the basis of the Almazov National Medical Research Centre (Saint Petersburg, Russia) is presented.Results. Analysis of the published results of treatment of patients with epidural arachnoid cysts showed that the main task facing the surgeon is to identify and close the communication between the cyst and the subdural space. To accurately determine the localization of the dura mater defect and minimize operative access, many authors consider computed tomography myelography to be effective.Conclusion. Despite the variety of existing diagnostic methods, a specific and accurate way to visualize the defect has not been found to date. Based on the analysis of the literature, it can be said that the rarity of publications on this topic makes even individual reports relevant, and today there is no way to propose a specific strategy for the diagnosis and surgical treatment of such cysts.

COMPARISON OF THE EFFICIENCY OF THE CLOSURE OF DEFECTS OF DURA MATER WITH HIGH-FREQUENCY ELECTRIC WELDING TO TRADITIONAL SEWING CONNECTION

A comparison of the effectiveness of closure of dura mater defects in the surgical removal of tumors of the frontal sinuses with intracranial snvaiding by methods of high-frequency electric welding of tissues and traditional sutures. A comprehensive assessment of methods by a group of indicators for both direct surgery and rehabilitation period was used. Significant advantages of high-frequency bipolar electric welding in comparison with traditional seam connection are shown.Usage of biological welding contributes to a significant reduction of intra- and postoperative complications, shortening the operation time, reduced duration of postoperative treatment compared to traditional methods.

Combined transcranial and transnasal endoscopic approach in transnasal-penetrating intracranial injury: A rare case report.

IntroductionTransnasal-penetrating intracranial injuries are rare traumatic brain injuries that can cause serious and fatal brain damage and a high mortality rate and necessitate immediate multidisciplinary surgical management. We describe an uncommon case whereby a patient who presented with an accidental penetrating injury of the brain was found to have a wooden transnasal-penetrating intracranial object.Case presentationA 28-year-old man consulted an ear, nose, and throat (ENT) surgeon after complaints of headache for two days, a history of epistaxis, and vomitus. The right side of the nose had been punctured by wood as a result of falling from a motorcycle. A computed tomography (CT) scan led to diagnosis of a transnasal penetrating intracranial injury. Removal of the transcranial foreign body was carried out jointly by a neurosurgeon and ENT surgeon. Postoperatively, antibiotics were given for 14 days, and the patient was discharged without neurological deficit.Clinical discussionEarly diagnostic procedures, such as CT scan of the skull to assess trajectory and extent of vascular and brain tissue injury, are required for appropriate surgical planning and post-operative treatment of such patients. Surgery was performed by combined transcranial and transnasal endoscopy to identify the skull base, dura mater defect, and brain tissue damage. Removal of the corpus alienum by transnasal endoscopy yielded a good outcome.ConclusionCombined transcranial and transnasal endoscopic approach showed better result than transcranial approach only. The wooden foreign body can be completely eliminated transnasally without active bleeding using this approach. The patient was discharged with good outcome.

Treatment strategy for patients with thoracic and lumbar spine fractures with dura mater tear

Background. The dura mater tear are quite common in patients with thoracic and lumbar fractures. Prevention and management of cerebrospinal fluid leakage and sealing of the dura mater suture is an important stage in the treatment of such patients.Objective: to find an optimal surgical tactics for patients with fractures of the thoracic and lumbar spine and dura mater tear.Materials and methods. This study included 167 patients operated on for fractures of the thoracic and lumbar spine with concomitant traumatic spinal canal stenosis. We analyzed their clinical data and results of instrumental examination. All patients underwent laminectomy at the level of their fractures and transpedicular fixation. The main group included 55 patients with dura mater tear, whereas the control group comprised 112 patients without dura mater tear.Results. Dura mater tear was found in 32.9 % of patients with fractures of the thoracic and lumbar spine. Of them, 21.8 % had compression of the spinal cord or nerve roots at the sites of dura mater tear. This fact should be taken into account when performing decompression and the reduction maneuver to prevent additional injuries to the neural structures. Thirty-three (60.0 %) patients underwent direct suturing aimed to restore the dura mater integrity. Their mean size of the dura mater tear was 13.2 ± 7.4 mm2. Thirteen patients (23.6 %) with larger dural tear (27.5 ± 6.3 mm2) underwent their repair using either a fragment of dura mater from a deceased donor (n = 2), Reperen implants (n = 5), or Durepair patches (n = 6). In 9 patients (16.4 %), the integrity of dura mater was restored without suturing (the «sandwich»-sealing method) (mean size of the dura mater defect 5.0 ± 2.6 mm2). Twenty-one patients had additional sealing of dura mater suture using bioglue.Postoperative wound cerebrospinal fluid leakage was registered in 5 out of 55 patients from the main group. Cerebrospinal fluid leakage was most common in patients who had undergone dura mater repair with implants (23.1 %), while those who had undergone direct dura mater suturing were less likely to develop it (6.1 %). No cerebrospinal fluid leakage was observed in patients with small defects (≤3 mm2) or in those whose dural tears were located at the nerve root cuffs. Patients with postoperative cerebrospinal fluid leakage had no additional sealing of dura mater suture using bioglue.Postoperative wound infection was registered in 4 (7.3 %) patients from the main group and 6 (5.4 %) patients from the control group.Conclusion. Sealing of dura mater sutures with glue compositions is an effective method to prevent postoperative cerebrospinal fluid leakage. Sealing of dura mater sutures with a collagen sponge does not prevent wound cerebrospinal fluid leakage.

EARLY METHODS OF PREVENTION AND TREATMENT OF POSTOPERATIVE PSEUDOMENINGOCELE OF THE HEAD

To summarize the accumulated experience and compare the available materials for plastic surgery of dura mater (DM) defects. An increasing number of patients who have suffered a traumatic brain injury and an increasing number of neurosurgical operations for tumor processes, congenital malformations leads to an increase in the number of DM defects and related complications. Despite the development of technologies for obtaining highly effective medical devices, the percentage of postoperative liquorrhea is still high, with subtentorial localization of the defect reaches 32%. Complications such as pseudomeningocele, postoperative inflammatory processes, liquorrhea, implant rejection, scar-adhesive processes leave unresolved the question of finding a suitable substitute for DM defects. The article presents an overview of the main materials for closing defects of DM: autografts, biological, synthetic materials. Their positive and negative qualities are discussed depending on the type and localization of damage, the type of material used. The analysis of the main characteristics that an ideal substitute for DM should correspond to is carried out. Composite materials are considered as a promising direction for the development of modern bioengineering.

Histopathological effect of platelet-rich plasma on cranial dura mater defects

There are many new studies in the selection of materials used in dura material repair. Platelet has important function in hemostasis and coagulation. Also, activated platelets initiate the wound healing process. They provide regeneration of tissue with the appropriate type of tissue. In this experimental study, we used platelet-rich plasma (PRP) on dura mater defect due to these properties. Materials and method: Our study started after we got the approval of Ondokuz Mayıs University Animal Experiments Local Ethics Committee. Thirty Wistar Albino female rats were used. The rats were divided into three groups, each one includes ten. Results: No significant difference was observed in the thickness and surface areas of dura mater in group 1 and group 2. Significant increase was observed in the thickness and surface areas of dura mater in the PRP applied group (Group 3) compared to other groups. New bone areas and new vasculature were observed more frequently in the PRP rooms group (Group 3). Statistical analysis of the data was done by using SPSS 21.0 for Mac (IBM Corporation) statistical package program and based on 0.05 significance level. A significant difference was observed between Group 1 and Group 3 (p> 0.05), a significant difference was observed between both Group 1 and Group 3 and between Group 2 and Group 3 (p <0.05). Conclusion: Providing the regeneration of dura mater in defect situations will contribute to the protection of the barrier feature. In line with this idea, it is thought that PRP can be beneficial for us to reach this goal.

Expanding pneumocephalus due to craniofacial fractures: A case report.

IntroductionPneumocephalus (PNC) is the presence of air in the intracranial cavity. The most frequent cause is craniofacial trauma, though there are many etiologies, including surgical procedures. PNC with compression of the frontal lobes and widening of the interhemispheric space between the tips of the frontal lobes results in the characteristic radiological finding of the “Mount Fuji sign”.Presentation of caseA 57-year-old man presented to the A&E with loss of consciousness due to a motorcycle collision 9 h prior. He had a GCS of E4M6V5, and a head CT scan revealed minimal PNC forming in both hemispheres. After discharge, severe headaches and rhinorrhea developed. A second CT scan revealed a massive PNC. An operation was then performed via a bicoronal incision to drain the PNC and seal the cranial defect. A burr hole in the calvarium was created, and the cranial defect was closed using a pericranial rotational flap. Post-operation, the patient's headache and rhinorrhea decreased; neither symptom was present at 1-month post-operation. The wounds healed with minimal scarring, and the cosmetic outcome for the craniofacial fracture was acceptable.DiscussionAlthough the patient may at first present with a mild head injury, this can progress into something much more serious. PNC is difficult to diagnose clinically. Rarely, patients describe a splashing sound upon moving the head (termed bruit hydro-aerique), which can also be auscultated. A head CT scan is the gold standard in the diagnosis of PNC. Pericranial flaps are widely used for dural repair because they are easily accessible and have a lower rate of infection than artificial grafts on expanding PNC.ConclusionTension PNC may be slow-growing and increase intracranial pressure to high levels before clinical signs are present. The pericranial rotational flap technique is the best way to close a dura mater defect in cranial base fractures with tension PNC.

Review of dura mater substitutes in neurosurgical practice

AIM: This study aimed to summarize the accumulated experience and compare available materials for the plasty of dura mater (DM) defects. The growing number of patients with craniocerebral traumas and an increasing amount of neurological surgeries for tumor processes and congenital malformations resulted in an increased amount of DM defects and associated complications. Despite the development of high-efficiency medical products, the percentage of postsurgical CSF leakage remains high and reaches 32% in case the defect is in infratentorial locations. Suitable substitute materials should be developed for the repair of dural defects because of complications such as pseudomeningocele, postsurgical inflammatory processes, CSF leakage, implant rejection, and cicatrical adhesion. In this article, basic materials, including auto- and allografts, biological substances, and synthetic materials, for the repair of dural defects were reviewed. Their positive and negative properties depending on the kind and location of lesions and on the type of material used were discussed. The main characteristics to be fulfilled by an ideal dura mater substitute were analyzed. Composite materials were considered a promising trend in modern bioengineering.
 CONCLUSION: An ideal material for the repair of DM defects should have the following properties: plastic, nonimmunogenic, watertight, highly porous, high surface area of fibers, cell growth stimulating, supportive for the survival of cells until they completely integrate with host tissues, conveniently replaceable, and adhesive. No ideal transplant materials can meet all the above demands. Biological, synthetic, and host tissues only supplement one another. Relevant studies have yet to be performed to obtain a more versatile and time and cost effective material that can satisfy all the requirements of modern neurosurgery. The existing results of preclinical studies have demonstrated that composite materials are similar to synthetic materials in terms of the strength and properties of biological tissues for the migration and proliferation of cells. In the future, they may become a promising alternative to biological substitutes.

Initial Histological Evaluation of a Novel Dura Mater Graft Based on Capsule Granulation Harvested From Subcutaneous Tissue: Experimental Model.

Autografts are useful but unfortunately are limited in big dural defects, in such cases, synthetic implants have been recommended. Extensive evidence in the literature suggests that sometimes synthetic implants had high rates of complications like infections. This paper aims to present a novel dura matter graft based on capsule granulation tissue harvested from subcutaneous space as a dura substitute and its histological findings. Wistar rats between 240 and 430 grams of both genders were included. First stage procedure introducing silicon spheres in the subcutaneous tissue. Second stage procedure 4 weeks later harvested de capsule granulation tissue that contain them. Then a craniectomy was performed to create a dura mater defect. This defect was reconstructed with the granulation tissue was placed onlay the defect. After another 4 weeks the subjects were euthanized and sent to an external pathology unit for analysis with validated integration scales. A total of 5 subjects were included (3 males and 2 females) with weight between 240 and 430 grams. Only 2 outcome out of 6 scales had significance difference between the samples: adhesions P = 0.011 and integration P = 0.006. The histological findings shown that capsule granulation graft is a compatible, autologous compatible substitute for dura mater. It has a great potential of full integration and an acceptable grade of adhesions.

The Effect of Adding Modified Chitosan on the Strength Properties of Bacterial Cellulose for Clinical Applications.

Currently, several materials for the closure of the dura mater (DM) defects are known. However, the long-term results of their usage reveal a number of disadvantages. The use of antibiotics and chitosan is one of the major trends in solving the problems associated with infectious after-operational complications. This work compares the mechanical properties of samples of bacterial nanocellulose (BNC) impregnated with Novochizol™ and vancomycin with native BNC and preserved and native human DM. An assessment of the possibility of controling the mechanical properties of these materials by changing their thickness has been performed by statistical analysis methods. A total of 80 specimens of comparable samples were investigated. During the analysis, the results obtained, the factor of Novochizol™ addition has provided a statistically significant impact on the strength properties (Fisher Criteria p-value 0.00509 for stress and 0.00112 for deformation). Moreover, a stronger relationship between the thickness of the samples and their ultimate load was shown: for BNC + Novochizol™ + vancomycin, compared to for native BNC. Using factor analysis, it was possible to show a significant effect of modified chitosan (Novochizol™) on the ultimate stress (p-value = 0.005).

A biomimetic triple-layered biocomposite with effective multifunction for dura repair

Dura mater defect and subsequent cerebrospinal fluid (CSF) leakage usually appear in trauma or neurosurgical procedures and are followed by a series of serious complications and even death. The use of a qualified dura mater substitute with multifunction of leakage blockade, adhesion prevention, and dura reconstruction is one of the promising treatment methods. However, even though some products have been used in the clinic, none of the substitutes achieved the required multifunction. In this study, we aimed to design and fabricate a dura repair composite with the ideal multifunction. By biomimicking the structure and component of natural dura, we applied poly(L-lactic acid) (PLLA), chitosan (CS), gelatin, and acellular small intestinal submucosa (SIS) powders to successfully prepare a triple-layered composite. Then, a series of specific devices and techniques were developed to investigate the performance. The results revealed that satisfactory structural stability could be realized under good synergistic interactions among the components. In addition, all the findings suggested that the bionic triple-layered composite showed satisfactory multifunction of leakage blockade, adhesion prevention, antibacterial property, and dura reconstruction potential, and thus, it might be a promising candidate for dura repair. Statement of significanceDeveloping qualified dura mater substitutes with multifunction of leakage blockade, adhesion prevention, and dura reconstruction is crucial for treating dura mater defect and subsequent cerebrospinal fluid (CSF) leakage that appear in trauma or neurosurgical procedures. In this study, we designed and fabricated a triple-layered dura repair biocomposite with satisfactory structural stability and desired multifunction based on biomimicking of the structure and component of natural dura. Moreover, a series of specific devices and techniques were developed to investigate the relevant performance. Overall, the developed hydrogel electrospinning system exhibited excellent advantages in achieving multifunction and could be applied widely in the future to achieve multifunctional tissue repair materials.