Table 2.

Non-biological materials and their effect evaluation

Ref.	Year	Restorative materials	Object of application	Evaluation of clinical / laboratory effect
Ramot et al[94]	2020	Novel synthetic and fibrous Dural graft: Poly (L-lactic-cocaprolactone acid) and poly (D-lactic-co-caprolactone acid)	Rabbits	12 mo after operation, there was no animal death, and the new dura mater, dura mater injury and upper bone healing were formed at the implantation site. The advantage for this material is favorable local tolerability and biodegradability
Schmalz et al[53]	2018	Cerafix dura substitute: Spun poly (lactic-coglycolic acid) and poly-p-dioxanone	Human: Four patients after resection of brain tumor	In all patients wound healing proceeded without complication. There was no imaging evidence of persistent fluid collection to suggest cerebrospinal fluid leakage or pseudomeningocele formation, nor was there evidence of meningeal enhancement to suggest the development of subclinical chemical meningitis
Li et al[60]	2022	bioactive patch composed of alginate and polyacrylamide hydrogel matrix cross-linked by calcium ions, and chitosan adhesive	In vitro experiment and in vivo experiment in rabbit model	The bioactive patch have the good properties of withstanding high pressure, promoting defect closure, exerting the effects of anti-inflammatory, analgesic, adhesion prevention and inhibiting postoperative infection
Kinaci et al[58]	2021	Liqoseal, a dural sealant patch comprising a watertight polyester-urethane layer and an adhesive layer consisting of poly (DL-lactide-co-ε-caprolactone) copolymer and multi-armed N-hydroxylsuccinimide functionalized polyethylene glycol	Computer-assisted models, fresh porcine dura and In vitro experiment	The mean burst pressure of Liqoseal in the spinal model (233 ± 81 mmHg) was higher than that of Tachosil (123 ± 63 mmHg) and Tisseel (23 ± 16 mmHg). Compared with Adherus, Duraseal, Tachosil, and Tisseel, Liqoseal was able to achieve a strong watertight seal on dura defects in the in vitro model
Yamaguchi et al[56]	2019	Durawave: Polyglycolic acid felt	Human: 36 cases of tumor resection via transpetrosal approach	The cerebrospinal fluid leakage rate of patients treated with polyglycolic acid felt was lower than that of autogenous fascia fixation, and the time of intraoperative dural reconstruction was significantly shortened. Using polyglycolic acid felt to reconstruct dura mater simplifies the operation and may prevent cerebrospinal fluid-related complications after transpetrosal approach
Huang et al[61]	2022	Photo-Crosslinked Hyaluronic Acid/Car-b oxymethyl Cellulose Composite Hydrogel	In vitro experiment and in vivo experiment in rabbit model	It has biocompatibility, biodegradability and mechanical strength. By drastically reducing attachment and penetration of adhesion-forming fibroblasts in vitro, HC hydrogel can be used as an anti-adhesion barrier to prevent postoperative adhesion
Zhu et al[95]	2021	Tetra-PEG hydrogel sealants	In vitro experiment and in vivo experiment in rabbit model	It has the advantages of simple operation, high safety, fast solidification time, easy injection, good mechanical strength and strong tissue adhesion. In the liquid environment, the tetra-PEG hydrogel sealants can also instantly adhere to the irregular tissue surface
Chuan et al[57]	2020	Stereocomplex nanofiber membranes based on enantiomeric poly (lactic acid) and poly (D-lactic acid)-grafted tetracalcium phosphate	In vitro experiment	It has heat resistance, stretching similar to human dura mater, non-toxic to cells, and neuron compatibility
Yu et al[62]	2015	Two layers of novel electrospun membranes, dermal fibroblasts and mussel adhesive protein for repairing spinal dural defect. Inner layer: Lactide-co-glycolide other layer: Chitosan-coated electrospun nonwoven poly(lactide-co-glycolide) membrane	Goats	Seamless and quick sealing of the defect area with the implants was realized by mussel adhesive protein. Effective cerebrospinal fluid containment and anti-adhesion of the regenerated tissue to the surrounding tissue could be achieved in the current animal model
Masuda et al[96]	2016	Suture or nonpenetrating titanium clips, followed by reinforcement with a polyglycolic acid mesh and fibrin glue intraoperatively	75 patients (34 males and 41 females; age range, 16e80 years; mean age, 57.1 years)	Only one patient out of 75 (1.3%) required reoperation for dural repair
Terasaka et al[64]	2017	Fibrin glue and polyglycolic acid felt (GM111)	Sixty patients were enrolled. The craniotomy site was supratentorial in 77.2%, infratentorial in 12.3% and sellar in 10.5%	Cerebrospinal fluid leakage and subcutaneous cerebrospinal fluid retention throughout the postoperative period were found in four patients. Adverse events for which a causal relationship with GM111 could not be ruled out occurred in 8.8% of the patients. There were no instances of postoperative infection due to GM111
Liao et al[97]	2021	Triple-layered composite: Poly (L-lactic acid), chitosan, gelatin, and acellular small intestinal submucosa	In vitro experiment	Satisfactory multifunction of leakage blockade, adhesion prevention, antibacterial property, and dura reconstruction potential
Deng et al[66]	2017	Absorbable materials Poly (L-lactic acid) and gelatin	In vitro experiment	More biomimetic to native extracellular matrix than collagen substitute did, together with better cytocompatibility, tissue ingrowth, and neoangiogenesis

PLLA: Poly (L-lactic acid).