Non-thermal Atmospheric Plasma Treatment Research Articles

Tailoring surgical sutures with chitosan and non-thermal atmospheric plasma: biofunctionalization for antimicrobial efficacy and enhanced wound healing

Surgical sutures serve as medical devices designed to facilitate the closure of wounds by securing opposing tissues. While sutures are an integral part of the surgical healing process, also present favorable surfaces for microbial attachment, increasing surgical site infections (SSIs). In this study, sutures that have antimicrobial and improved wound healing properties are described as novel approaches for minimizing SSIs. The absorbable multifilament suture, poly (glycolic-co-lactic acid) (PGLA), and non-absorbable multifilament suture (silk) are treated with non-thermal atmospheric plasma (NTAP) and subsequently coated with chitosan/chitosan nanoparticles (Ch/ChNp). Suture samples are analyzed in terms of antibacterial properties, in vitro bioactivity, wound healing efficiency, mechanical strength, chemical characterization, and surface morphologies. Bacterial adherence of Staphylococcus aureus and Escherichia coli on both sutures is inhibited effectively due to the surface modification after plasma treatment. The NTAP treatment results in reduced wound healing for silk sutures without a selective effect on PGLA sutures. However, subsequent coating with Ch/ChNp significantly enhances wound healing for both sutures. Although the maximum tensile strength decreases after NTAP treatment, improves following the Ch/ChNp coating. Our findings indicate that the developed sutures demonstrate notable antimicrobial properties, enhance wound healing, and hold promise as a potential material for suturing applications.

How Mucilaginous Seeds of Different Plant Species Respond to Nonthermal Atmospheric Plasma Treatment

How Mucilaginous Seeds of Different Plant Species Respond to Nonthermal Atmospheric Plasma Treatment

Nonthermal Plasma Treatment Can Eliminate Sandblasting Procedure For Zirconia-Resin Cement Bonding.

To evaluate the effects of nonthermal atmospheric plasma (NTAP) treatment, alone or combined with sandblasting and/or primer application, on the bonding of zirconia ceramics to resin cement. Materıals and Methods: A total of 420 discs of Y-TZP (2 x 15 x 12 mm) were prepared and randomly divided into 10 groups according to surface treatment, as follows: Z (control), SB (sandblasting), Pr (primer), SBPr (sandblasting + primer), P (NTAP), SBP (sandblasting + NTAP), PrP (primer + NTAP), SBPrP (sandblasting + primer + NTAP), PPr (NTAP + primer), and SBPPr (sandblasting + NTAP + primer). After surface treatments, the surface roughness values were evaluated using a profilometer, and the contact angle measurements were performed using a goniometer. Surface characterizations of the groups were analyzed using scanning electron microscopy and x-ray photoelectron spectroscopy analyses. Shear bond strength tests were performed after adhesive cementation in 20 specimens per group, with half (n = 10) subjected to thermocycling (5,000 cycles, 5°C to 55°C). The failure mode was recorded by examining each specimen using a stereomicroscope. One-way and two-way ANOVA followed by Student-Newman-Keuls test (α = .05) were used to analyze the data statistically. Untreated zirconia surfaces (without sandblasting) were found to have a higher wettability and oxygen ratio after NTAP treatment. The clinical application order of NTAP is an important factor, and the best combination for bonding quality was NTAP treatment followed by primer application on untreated zirconia (group PPr), rather than on a sandblasted surface. Conclusıon: NTAP application may be a promising surface treatment method for adhesive cementation of zirconia ceramics as an alternative to sandblasting. To achieve strong adhesion, NTAP should be applied before primer aplication.

Comparison of early osseointegration of non-thermal atmospheric plasma-functionalized/ SLActive titanium implant surfaces in beagle dogs.

Background: Hydrophilic dental implants are gaining increasing interest for their ability to accelerate bone formation. However, commercially available hydrophilic implants, such as SLActive™, have some major limitations due to their time-dependent biological aging and lower cost-effectiveness. The non-thermal atmospheric plasma (NTAP) treatment is a reliable way to gain a hydrophilic surface and enhance osseointegration. However, a few studies have been carried out to compare the osseointegration of NTAP-functionalized titanium implants and commercially available hydrophilic implants. Purpose: In this study, we compare the osseointegration abilities of the NTAP-functionalized titanium implant and Straumann SLActive. Material and methods: The NTAP effectiveness was examined using in vitro cell experiments. Then, six beagle dogs were included in the in vivo experiment. Straumann SLActive implants, SLA implants, and SLA implants treated with NTAP were implanted in the mandibular premolar area of dogs. After 2 w, 4 w, and 8 w, the animals were sacrificed and specimens were collected. Radiographic and histological analyses were used to measure osseointegration. Results: NTAP treatment accelerated the initial attachment and differentiation of MC3T3-E1 cells. In the in vivo experiment, bone parameters (e.g., BIC value and BV/TV) and volume of new bone of NTAP groups were close to those of the SLActive group. Additionally, although there was no statistical difference, the osseointegration of SLActive and NTAP groups was evidently superior to that of the SLA group. Conclusion: NTAP-functionalized implants enhanced cell interaction with material and subsequent bone formation. The osseointegration of the NTAP-functionalized implant was comparable to that of the SLActive implant at the early osseointegration stage.

A novel approach for microalgal cell disruption and bioproducts extraction using non-thermal atmospheric plasma (NTAP) technology and chitosan flocculation

Microalgal cell disruption and bio-product extraction still remain as major challenging steps for biomass downstream processing. In this study, a sustainable approach of using non-thermal atmospheric plasma (NTAP) and chitosan flocculation was developed for microalgal cell disruption and bio-product recovery from wet C. Sorokiniana. For this purpose, the performance of NTAP treatment for cell disruption and extraction of protein, carbohydrate and lipid was investigated by using different applied voltages (8–16 kV). Then, the application of chitosan on recovery of bioproducts from the culture medium was evaluated. Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) images were used to analyze the flocculation mechanism and for flocs characterization. Additionally, the energy consumption and efficiency of the NTAP process were analyzed. According to the NTAP results, the highest cell disruption of 75% was achieved under the applied voltage of 16 kV. However, in the case of bioproducts extraction, the optimal applied voltage was 12 kV which was able to yield 41, 24 and 36 (%CDW) of protein, carbohydrate and lipid, respectively. Adding 100 mg/L chitosan efficiently recovered the released protein (65%) and carbohydrate (85%) from culture medium, while the highest lipid recovery (60%) was achieved at 150 mg/L chitosan addition. This study proved that the utilization of NTAP and chitosan treatment can be considered as a promising approach for valuable products extraction from microalgae.

Involvement of PI3K/Akt signaling pathway in promoting osteogenesis on titanium implant surfaces modified with novel non-thermal atmospheric plasma.

Non-thermal atmospheric plasma (NTAP) modification to induce a hydrophilic titanium (Ti) surface with less carbon contamination, has been demonstrated to boost the osteogenic responses. In this study, we investigated the underlying bone formation mechanism of NTAP-Ti, and the involvement of PI3K/Akt signaling pathway in regulating osteogenic activities on NTAP-Ti surfaces. NTAP was employed for Ti activation, and PI3K inhibitor, LY294002, was applied to the suppression of PI3K/Akt pathway. We systematically and quantitatively detected the cell morphology, attachment, proliferation, osteogenic differentiation and mineralization of MC3T3-E1 mouse preosteoblasts, and molecular expressions involved in osteogenesis and PI3K/Akt signaling pathway in vivo and in vitro. A descent in osteoblast proliferation on Ti surfaces in relation to LY294002. Alkaline phosphatase (ALP) activity, as well as matrix mineralization, was mitigated by PI3K inhibitor in NTAP-Ti. Likewise, the expression levels of osteogenesis-related genes [ALP, osteocalcin (Ocn), osteopontin (Opn) and runt-related transcription factor 2 (Runx2)] on NTAP-Ti were notably attenuated by LY294002, as confirmed by the results of osteogenesis-related proteins (ALP, and Runx2) expression analysis. In addition, the expression of PI3K/Akt signal pathway proteins further verified the inhibition of LY294002 on Ti surfaces modified by NTAP. Collectively, the PI3K/Akt signal pathway was involved in the amelioration of osteogenesis induced by NTAP modification. NTAP treatment for Ti activation is promising in augmented osteogenic potential through the activation of PI3K/Akt signal pathway.

Promoting the adhesion of human gingival epithelial cells on titanium surface by non-thermal atmospheric plasma irradiation.

This work aimed to study the biological behavior of human gingival epithelial cells (HGECs) irradiated by non-thermal atmospheric plasma (NTAP) on a titanium surface. Cultured HGECs (3⁃5 generations) with the best activity were digested and treated for varying times (0, 10, 20, 30, and 60 s) by NTAP and then seeded on the surface of a titanium disc. The HGECs were cultured in oral keratinocyte medium and 1% penicillin/streptomycin solution. The cells were kept in an atmosphere of 5% CO2 at 37 ℃ and incubated for different times (4, 12, 24, and 48 h; n=5). Cell counting kit-8 (CCK-8) was used to detect cell adhesion capacity. Scanning electron microscopy (SEM) was conducted to observe the morphology of cells on titanium plates. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to evaluate the gene expression of adhesion-related molecules, such as Laminin α3, Integrin β4, and Plectin. The number of adhered cells increased at 0‑20 s, whereas that gradually decreased at 20⁃60 s. Therefore, cell culture at the two time points showed that HGECs adhesion reached the maximum when NATP was irradiated for 20 s. Compared with the control group, more cells in the treatment group adhered to the titanium surface at each time point (P<0.05). Cells in the treatment group showed more irregular polygons, more protrusions and pseudopods, and a larger cell diffusion area on the titanium surface than those in the control group. qRT-PCR showed that the expression levels of Laminin α3, Integrin β4, and Plectin adhesion-related genes on the titanium surface in the treatment group were higher than those in the control group at each culture time point (P<0.05). Western blot showed that the expression levels of Laminin α3, Integrin β4, and Plectin adhesion-related proteins on the titanium surface were higher in the treatment group than in the control group at 4 and 12 h. After NTAP treatment, the results showed that 20 s of treatment time could maximize the number of adhered cells on the titanium surface; change the cell adhesion morphology; and significantly upregulate the expression of adhesion-related genes and proteins of Laminin α3, Integrin β4, and Plectin. Furthermore, it could promote the biological sealing effect of HGECs on the titanium surface.

Effects of non-thermal atmospheric plasma on protein.

Currently, the advancement in non-thermal atmospheric plasma technology enables plasma treatments on some heat-sensitive targets, including biological substances, without unspecific damage caused by thermal effect. The significant effects of non-thermal atmospheric plasma modulating biological events have been demonstrated by considerable studies. Protein, one of the most important biomolecules, participates in the majority of the life-sustaining activities in all organisms, whose functions are derived from the diverse biochemical properties of amino acid compositions and four-tiered protein structure hierarchy. Therefore, the knowledge of how non-thermal atmospheric plasma affects protein greatly benefits the understanding and application of the non-thermal atmospheric plasma's effect in biological area. In this review, we summarize recent research progress on the effects of non-thermal atmospheric plasma, particularly its reactive species, on biochemical and biophysical characteristics of proteins at different structural levels that leads to their functional changes. Moreover, the physiological effects of non-thermal atmospheric plasma at cellular or organism level driven by the manipulations on protein and their relative application prospects are reviewed. Despite the exceptional application potential, the exploration of the non-thermal atmospheric plasma's effect on protein still confronts with difficulties due to the limited knowledge of the underlying mechanisms and the complexity of non-thermal atmospheric plasma operation systems, which requires further studies and standardization of non-thermal atmospheric plasma treatments.

Antibacterial efficacy of non-thermal atmospheric plasma against Streptococcus mutans biofilm grown on the surfaces of restorative resin composites

The aim of this study was to evaluate the antimicrobial efficacy of non-thermal atmospheric plasma (NTAP) against Streptococcus mutans biofilms. Resin discs were fabricated, wet-polished, UV sterilized, and immersed in water for monomer extraction (37 °C, 24 h). Biofilms of bioluminescent S. mutans strain JM10 was grown on resin discs in anaerobic conditions for (37 °C, 24 h). Discs were divided into seven groups: control (CON), 2% chlorhexidine (CHX), only argon gas 150 s (ARG) and four NTAP treatments (30 s, 90 s, 120 s, 150 s). NTAP was applied using a plasma jet device. After treatment, biofilms were analyzed through the counting of viable colonies (CFU), bioluminescence assay (BL), scanning electron microscopy (SEM), and polymerase chain reaction (PCR). All NTAP-treated biofilm yielded a significant CFU reduction when compared to ARG and CON. BL values showed that NTAP treatment for 90 s, 120 s or 150 s resulted in statistically significantly lower metabolic activity when compared to the other groups. CHX displayed the lowest means of CFU and BL. SEM showed significant morphological changes in NTAP-treated biofilm. PCR indicated damage to the DNA structure after NTAP treatment. NTAP treatment was effective in lowering the viability and metabolism of S. mutans in a time-dependent manner, suggesting its use as an intraoral surface-decontamination strategy.

Effect of Non-thermal Atmospheric Plasma on Viability and Histamine-Producing Activity of Psychotrophic Bacteria in Mackerel Fillets.

Non-thermal atmospheric plasma (NTAP) has gained attention as a decontamination and shelf-life extension technology. In this study its effect on psychrotrophic histamine-producing bacteria (HPB) and histamine formation in fish stored at 0–5°C was evaluated. Mackerel filets were artificially inoculated with Morganella psychrotolerans and Photobacterium phosphoreum and exposed to NTAP to evaluate its effect on their viability and the histidine decarboxylase (HDC) activity in broth cultures and the accumulation of histamine in fish samples, stored on melting ice or at fridge temperature (5°C). NTAP treatment was made under wet conditions for 30 min, using a dielectric barrier discharge (DBD) reactor. The voltage output was characterized by a peak-to-peak value of 13.8 kV (fundamental frequency around 12.7 KHz). This treatment resulted in a significant reduction of the number of M. psychrotolerans and P. phosphoreum (≈3 log cfu/cm2) on skin samples that have been prewashed with surfactant (SDS) or SDS and lactic acid. A marked reduction of their histamine-producing potential was also observed in HDC broth incubated at either 20 or 5°C. Lower accumulation of histamine was observed in NTAP-treated mackerel filets that have been inoculated with M. psychrotolerans or P. phosphoreum and pre-washed with either normal saline or SDS solution (0.05% w/v) and stored at 5°C for 10 days. Mean histamine level in treated and control groups for the samples inoculated with either M. psychrotolerans or P. phosphoreum (≈5 log cfu/g) varied from 7 to 32 and from 49 to 66 μg/g, respectively. No synergistic effect of SDS was observed in the challenge test on meat samples. Any detectable amount of histamine was produced in the meat samples held at melting ice temperature (0–2°C) for 7 days. The effects of NTAP on the quality properties of mackerel’s filets were negligible, whereas its effect on the psychrotrophic HPB might be useful when time and environmental conditions are challenging for the cool-keeping capacity throughout the transport/storage period.

Effect of nonthermal atmospheric plasma on the shear bond strength of composite resin after using different tooth-whitening systems: An in vitro study.

Aim:We aimed to evaluate the effect of nonthermal atmospheric plasma (NTAP) on the bond strength of composite resin after using different tooth-whitening systems.Methods:Eighty maxillary central incisors (n = 80) were divided into two groups based on the tooth-whitening procedure used – Group 1: bleaching (Pola Office, USA), Group 2: microabrasion (Opalustre, Australia). The samples were subdivided into four groups depending on the surface treatments – Group A: control (no surface treatment), Group B: plasma, Group C: antioxidant (sodium ascorbate), and Group D: buffering agent (sodium bicarbonate). After the surface treatments, the specimens were stored in artificial saliva for 24 h and composite resin was bonded to the labial surface of the teeth perpendicular to the long axis. The samples were then subjected to shear bond strength test under the universal testing machine.Statistical Analysis:The results received from shear bond strength analysis were subjected to statistical analysis using a two-way ANOVA test, independent t-test, and Tukey's multiple post hoc tests. The P value set was <0.05.Results:The highest mean bond strength value was seen in Group 2B (NTAP treatment after microabrasion) followed by Group 1B (NTAP treatment after bleaching). Mean shear bond strength values have suggested a statistically significant difference between all the other groups (P < 0.05) except between Groups 1A, 2A and 1D, 2D.Conclusions:Within the limitations of the current in vitro study, bleaching and microabrasion followed by surface treatment using NTAP showed the highest bond strength than other groups.

Comprehensive studies on the properties of apple juice treated by non-thermal atmospheric plasma in a flow-through system

We present an optimized non-thermal atmospheric plasma (NTAP)-based reaction-discharge system that was applied for a continuous-flow treatment of apple juice (AJ). To optimize this system for a high-throughput production of AJ with ameliorated properties, the effect of several parameters was studied using design of experiments approach followed by the response surface methodology. Additionally, nutritional, physicochemical, microbiological and cytotoxic properties of resulting AJ were assessed. It was established that NTAP treatment of AJ led to rise in concentration of Ca, Fe, K, Mg, Na and Sr by 8–10% as well as Al, B, Ba, Cu, Mn and Zn by 11–15%. Additionally, the increased total phenolic content by ~ 11% in addition to the prolonged by up to 12 days shelf life of the product were observed. Moreover, it was found that the NTAP-treatment of AJ did not change the structure of organic compounds present in AJ, in addition to its °Brix value, color and ferric ion reducing antioxidant power. Furthermore, AJ subjected to NTAP did not show any cytotoxic activity towards non-malignant human intestinal epithelial cells but exhibited induced cell cytotoxicity in human colorectal adenocarcinoma cells. Our study provided arguments for future introduction of these types of preparations to the global market.

Nonthermal Atmospheric Plasma-Induced Cellular Envelope Damage of Staphylococcus aureus and Candida albicans Biofilms: Spectroscopic and Biochemical Investigations

Objective: Nonthermal plasma at atmospheric condition using dielectric barrier discharge (DBD) is reported to be useful in many applications. Here, we have developed a strategy to generate nonthermal atmospheric plasma (NTAP) at ambient conditions for potential biomedical applications. Methods: We have explored the active ingredients of the nonthermal plasma using atomic emission spectroscopy. The potential mechanism of the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) from the generated plasma for therapeutic use has been demonstrated. Major results: The antimicrobial efficacy of the nonthermal plasma application to model Staphylococcus aureus and Candida albicans biofilms has been investigated. Our detailed electron microscopic studies followed by biochemical investigation reveal the mechanism of bacterial/fungal deactivation process. The nuclear magnetic resonance (NMR) studies on the live cell of C . albicans before and after NTAP treatment clearly conclude the disruption of cellular envelope leading to necrosis as evidenced by fluorescence-assisted cell sorting (FACS) studies. Conclusions: The proposed NTAP setup may find relevance in novel strategies in bacterial and fungal biofilm destruction in the future development of nonfluid hand sanitization.

Changes in enamel after bleaching pre-treatment with non-thermal atmospheric plasma

The aim of this study was to evaluate color change, mineral composition and topography of the enamel after the pre-treatment with non-thermal atmospheric plasma (NTAP) followed by 38% hydrogen peroxide (HP) bleaching.Buccal enamel of bovine incisors teeth was stained with black tea solution and then divided into five groups (n = 12), according to the plasma application time: PL1 (one minute) or PL2 (2 min) and number of HP applications: HP1 (one) and HP3 (three). The following groups were investigated: HP3, PL1+HP1, PL1+HP3, PL2+HP1 and PL2+HP3. Four color measurements: initial (untreated), after staining and after bleaching (first and second sessions), were performed using an intraoral spectrophotometer (Vita Easyshade). Energy Dispersive X-ray Spectroscopy (EDX) was used to analyze the mineral composition of the enamel before and after two bleaching sessions. Laser confocal microscopy was used to analyze the enamel topography.The pre-treatment with NTAP did not improve the whitening results. The use of NTAP preserves the concentration of calcium and phosphorus, only HP3 group experimented a significant decrease in the mineral concentration. All the bleached groups, with or without NTAP treatment increased their enamel roughness.The application of NTAP did not influence the color change, but it was important to maintain the mineral composition of bleached teeth. All the groups increased their roughness level.

Effects of novel non-thermal atmospheric plasma treatment of titanium on physical and biological improvements and in vivo osseointegration in rats

Titanium (Ti) has achieved extensive applications due to its excellent biocompatibility and mechanical properties. Plasma can enhance surface hydrophilia of Ti with decreased carbon contamination. The traditional conditions using a single gas plasma was for longer treatment time and more prone to being contaminated. We designed and developed novel and universal apparatus and methods with a special clamping device of non-thermal atmospheric plasma (NTAP) treatment using mixed gas for Ti surface activation. We systematically and quantitatively investigated the effective effects of NTAP-Ti. The surface water contact angle decreased by 100%, the carbon content decreased by 80% and oxygen content increased by 50% in the novel NTAP-Ti surfaces. NTAP treatment accelerated the attachment, spread, proliferation, osteogenic differentiation and mineralization of MC3T3-E1 mouse preosteoblasts in vitro. The percentage of bone-to-implant contact increased by 25–40%, and the osteoclasts and bone resorption were suppressed by 50% in NTAP-Ti in vivo. In conclusion, NTAP-Ti substantially enhanced the physical and biological effects and integration with bone. The novel and universal apparatus and methods with a special clamping device using gas mixtures are promising for implant activation by swiftly and effectively changing the Ti surface to a hydrophilic one to enhance dental and orthopedic applications.

Non-thermal atmospheric plasma treatment of onychomycosis in an in vitro human nail model.

SummaryBackgroundOnychomycosis affects almost 6% of the world population. Topical azoles and systemic antifungal agents are of low efficacy and can have undesirable side effects. An effective, non‐invasive therapy for onychomycosis is an unmet clinical need.ObjectiveDetermine the efficacy threshold of non‐thermal atmospheric plasma (NTAP) to treat onychomycosis in an in vitro model.MethodsA novel toe/nail‐plate model using cadaver nails and agarose media inoculated with Candida albicans was exposed to a range of NTAP doses.ResultsDirect exposure of C albicans and Trichophyton mentagrophytes to 12 minutes of NTAP results in complete killing at doses of 39 and 15 kPulses, respectively. Onset of reduced viability of C albicans to NTAP treatment through the nail plate occurs at 64 kPulses with 10× and 100× reduction at 212 and 550 kPulses, respectively.ConclusionsNTAP is an effective, non‐invasive therapeutic approach to onychomycosis that should be evaluated in a clinical setting.

Antibacterial effect of non-thermal atmospheric plasma against soft rot bacteria on paprika

Non-thermal atmospheric plasma (NTAP) was examined for its antibacterial activity of Pectobacterium carotovorum subsp. carotovorum on paprika. Bacterial populations were completely inhibited in response to NTAP treatment at 1000 W for 30 s–90 s. To further assess the mechanisms that NTAP treatment inactivates bacterial populations, the morphology and membrane damage of bacterial cells were analyzed. The bacterial cells treated with NTAP for 90 s at 1000 W exhibited noticeable disruption, hollowness, and roughness on the outer membrane surfaces accompanied by severe loss in membrane integrity, which indicates that cell death was caused by this significant membrane damage. NTAP treatment for 90 s induced DNA leakage from the Pcc membrane and caused significant DNA damage as assessed by qRT-PCR. On in vivo test, NTAP-treated paprika showed antibacterial effects by 40% compared to untreated samples. Our findings suggest the high applicability of NTAP in controlling postharvest bacteria and ensuring the preservation of paprika.

Pulsed xenon ultraviolet and non-thermal atmospheric plasma treatments are effective for the disinfection of air in hospital blood sampling rooms.

Non-thermal atmospheric plasma treatment and pulsed xenon ultraviolet (PX-UV) treatment are widely used in disinfection of hospital environments. However, their effectiveness has not been evaluated against a comparator. The objective of this study is to evaluate their effectiveness in the disinfection of pathogens in the air in hospital blood sampling rooms. Samples were taken from the air before and after disinfection with PX-UV and non-thermal atmospheric plasma. We counted bacterial colonies and identified the types of bacteria. Non-thermal plasma treatment significantly reduced bacterial counts in the air, the median reduced from 1 before treatment to zero afterwards (p = 0.03). PX-UV treatment also significantly reduced bacterial counts in the air (p = 0.01), the median reduced from 1.5 before treatment to zero afterwards. Pathogens identified in the current study include nosocomial bacteria, such as Staphylococcus aureus, Staphylococcus epidermidis, and yeast. Disinfection of blood sampling sites is essential in a health service department. The efficiency of PX-UV and non-thermal atmospheric plasma treatment are comparable in air disinfection.

Accelerated mineralization on nanofibers via non-thermal atmospheric plasma assisted glutamic acid templated peptide conjugation.

Surface modification by non-thermal atmospheric plasma (NTAP) treatment can produce significantly higher carboxylic groups on the nanofibers (NF) surface, which potentially can increase biomineralization of NF via promoting glutamic acid (GLU) templated peptide conjugation. Herein, electrospun poly(lactide-co-glycolide) (PLGA) scaffolds were treated with NTAP and conjugated with GLU peptide followed by incubation in simulated body fluids for mineralization. The effect of NTAP treatment and GLU peptide conjugation on mineralization, surface wettability and roughness were investigated. The results showed that NTAP treatment significantly increased GLU peptide conjugation which consequently enhanced mineralization and mechanical properties of NTAP treated and peptide conjugated NF (GLU-pNF) compared to neat PLGA NF, NTAP treated NF (pNF) and GLU peptide conjugated NF (GLU-NF). The effect of surface modification on human bone marrow derived mesenchymal stem cells adhesion, proliferation and morphology was evaluated by cell proliferation assay and fluorescent microscopy. Results demonstrated that cellular adhesion and proliferation were significantly higher on GLU-pNF compared to NF, pNF and GLU-NF. In summary, NTAP treatment could be a promising modification technique to induce biomimetic peptide conjugation and biomineralization for bone tissue engineering applications.

Prevention of Peritoneal Adhesions by Non-Thermal Dielectric Barrier Discharge Plasma Treatment on Mouse Model: A Proof of Concept Study

Purposes: Formation of peritoneal adhesions is a common consequence of abdominopelvic surgeries and remarkably increases the mortality and morbidity. Moreover, peritoneal adhesions linked to chronic abdominopelvic pain and infertility in women. Various attempts for prevention of peritoneal adhesions were reported. However, these methods either remain insufficient to prevent formation of peritoneal adhesions or carry some practical limitations and thus, there is a need for novel techniques that could effectively decrease the formation of peritoneal adhesions. The aim of the present prospective, randomized, controlled, and single blinded study was to evaluate the effect of non-thermal atmospheric plasma (NTAP) treatment on prevention of peritoneal adhesions. Materials and Methods: Sixteen male CD-1 mice were randomly divided into two groups: control and plasma. Excisional and abrasion adhesion models were generated on the peritoneal side wall and cecum, respectively. Ten days after creating adhesion models, mice were sacrificed and adhesion formations were evaluated macroscopically using Knightly’s and Linsky’s grading systems to assess the intensity and extent of adhesions, respectively. Zühlke’s grading system was used for microscopic assessment of adhesions. Results: The mean scores for peritoneum and cecum in control group according to Knightly’s grading system were determined as 3.3 and 2.6, respectively. In NTAP-treated group, Knightly’s score was determined as 1.6 and 0.5 for peritoneum and cecum, respectively. NTAP treatment reduced Linsky’s score from 3.8 to 1.3 and 2.1 to 1.1 on peritoneum and cecum. Finally, in microscopic evaluation, NTAP treatment reduced Zühlke’s score from 3.4 to 1.5 and 2.6 to 1.3 for peritoneum and cecum, respectively. Conclusions: The results of the present proof of concept study suggest that NTAP could be a novel method to reduce and/or prevent the formation of peritoneal adhesions after abdominopelvic surgeries.