Fuzzy analysis of 2-D wave equation through Hukuhara differentiability coupled with AOS technique.

The research article in hand provides a new mechanism that deals with the investigation of the triangular analytical fuzzy solutions (TAFS) of the two-dimensional fuzzy fractional order wave equation (2-D FFWE) through the Hukuhara conformable fractional derivative (HCFD) along with the concept of [gH] and [gH-p] differentiability. The mechanism consists of a fuzzy traveling wave method coupled with additive operating splitting (AOS). The procedure for the aforesaid mechanism starts with the extension of the HCFD to the fuzzy conformable fractional derivative (FCFD). Furthermore, some properties of FCFD that play a vital role in this study like, ([i-gH],[ii-gH],[i-p],[ii-p])-differentiability, switching point, fuzzy chain rule, and traveling wave method are discussed in detail. Further, fuzzy traveling wave method coupled with the procedure of the additive operating splitting (AOS) method is adopted to investigate the triangular analytical fuzzy solution of the Two-dimensional fuzzy wave equation (2-D FWE). Finally, some examples are provided that support our arguments.

Investigation of Dielectric, Ferroelectric, and Strain Responses of (1 - x)[0.90(Bi0.5Na0.5)TiO3 - 0.10SrTiO3] - xCuO Ceramics.

The low-temperature sintering of (Bi0.5Na0.5)TiO3-based ceramics can be achieved by sintering aid CuO. Piezoelectric ceramics (1 - x)[0.90(Bi0.5Na0.5)TiO3 - 0.10SrTiO3] - xCuO (BNT-ST-Cu) with x = 0, 0.01, 0.02, 0.03, and 0.04 were prepared through the mixed oxide route. A tetragonal structure was indexed for the undoped sample. Its structure was found to be changed to a pseudocubic when Cu was added. For undoped Cu samples, the sintering temperature (T s) for sufficient densification was 1160 °C. However, T s was reduced to 1090-1120 °C for Cu-added specimens. Field emission scanning electron microscopy (FE-SEM) showed a uniform and dense grain morphology for all samples. The maximum dielectric constant temperature (T m) was decreased with the doping concentration of Cu and applied frequency. The strain was increased with Cu concentration and had the maximum value of 500 pm/V for the sample x = 0.02 with symmetric and slim strain loops.

Anti-Alzheimer and Antioxidant Effects of Nelumbo nucifera L. Alkaloids, Nuciferine and Norcoclaurine in Alloxan-Induced Diabetic Albino Rats.

The present study is aimed to determine the efficacy and dose response of the nuciferine (1), norcoclaurine (2) and crude extract of Nelumbo nucifera in managements of diabetes, Alzheimer disease and related allergies. Experimentally, alloxan (100 mg/kg body weight (b.w.))-induced diabetic rats (200−250 g) were divided into seven groups (n = 6). Group I: normal control, Group II: diabetic control, Group III: standard treated with glibenclamide and Group lV-VII: treated with methanolic crude extracts (100, 200 mg/kg), nuciferine and norcoclaurine (10 mg/kg b.w.) for 15 days. Different tests were performed, including blood glucose, body weights and antioxidant enzyme assays, i.e., superoxide dismutase (SOD), catalase test (CAT), lipid peroxidation assay (TBARS), glutathione assay (GSH) and acetylcholinesterase (AChE) assay. Nuciferine and norcoclaurine significantly reduced blood glucose (p < 0.05) and restored body weight in diabetic rats. Moreover, nuciferine and norcoclaurine (10 mg/kg) significantly recovered the antioxidant enzymes (SOD, CAT, GPx and GSH) which decreased during induced diabetes. Significant increase in TBARS was also observed in the diabetic group and nuciferine as well as norcoclaurine (10 mg/kg) inhibited the increase in TBARS in diabetic animals (p < 0.05), as compared to glibenclamide. AChE activity was significantly recovered by nuciferine and norcoclaurine (10 mg/kg) both in the blood and brain of the diabetic group (p < 0.05). Nuciferine and norcoclaurine showed potent inhibitory effects against α-glucosidase and α-amylase with IC50, 19.06 ± 0.03, 15.03 ± 0.09 µM and 24.07 ± 0.05, 18.04 ± 0.021 µM, as confirmed by molecular docking studies. This study concludes that nuciferine and norcoclaurine significantly improve memory and could be considered as an effective phytomedicine for diabetes, Alzheimer's disease (AD) and oxidative stress.

Photocatalytic response in water pollutants with addition of biomedical and anti-leishmanial study of iron oxide nanoparticles.

Public health is a major concern globally, owing to the presence of industrial dyes in the effluent. Nanoparticles with green synthesis are an enthralling research field with various applications. This study deals with investigating the photocatalytic potential of Fe-oxide nanoparticles (FeO-NPs) for the degradation of methylene blue dye and their potential biomedical investigations. Biosynthesis using Anthemis tomentosa flower extract showed to be an effective method for the synthesis of FeO-NPs. The freshly prepared FeO-NPs were characterized through UV/Vis spectroscopy showing clear peak at 318 nm. The prepared FeO-NPs were of smaller size and spherical shape having large surface area and porosity with no aggregations. The FeO-NPs were characterized using XRD, FTIR, HRTEM, SEM and EDX. The HRTEM results showed that the particle size of FeO-NPs was 60-90 nm. The antimicrobial properties of FeO-NPs were investigated against two bacterial Staphylococcus aureus 13 (±0.8) and Klebsiella pneumoniae 6(±0.6) and three fungal species Aspergillus Niger, Aspergillus flavus, and Aspergillus fumigatus exhibiting a maximum reduction of 57% 47% and 50%, respectively. Moreover, FeO-NPs exhibited high antioxidant properties evaluated against ascorbic acid. Overall, this study showed high photocatalytic, antimicrobial, and antioxidant properties of FeO-NPs owing to their small size and large surface area. However, the ecotoxicity study of methylene blue degradation products showed potential toxicity to aquatic organisms.

Urease and α-Chymotrypsin Inhibitory Activities and Molecular Docking Studies of Alkaloids Isolated from Medicinal Plant Isatis minima Bunge.

Phytochemical studies on the alkaloids fraction of the entire plant of Isatis minima Bunge resulted in the alkaloids 1-4 isolation, which were first time isolated from this species. The 1D and 2D NMR spectroscopic data were used to identify their structures, and there was satisfactory compatibility of the data compared to those which were previously published. In the examined compounds 1-4, Isaindigotidione (3) and Isaindigotone (4) were shown as an effective urease inhibitor in such a concentration-dependent way against Jack bean and Bacillus pasteurii urease, with IC50 values 29.03 ± 0.04, 20.04 ± 0.09 and 34.03 ± 0.07, 26.13 ± 0.08 µM, respectively. Compounds 3 and 4 were likewise shown to be an effective inhibitor against α-chymotrypsin, exhibiting IC50 values 16.09 ± 0.07 and 22.01 ± 0.06 µM, correspondingly. The program MOE-Dock was used to perform a molecular docking analysis to confirm probable binding modes of the active complexes of the isolated compounds 1-4 and the crystal structure of urease and α-chymotrypsin enzymes. Compound 3 was the most active, having the highest docking scores against Bacillus pasteurii urease, α-chymotrypsin, and Jack bean (-8.6876), (-7.6647), and (-13.1927) µM, respectively. All four alkaloids (1-4) showed significant urease and protease inhibitory potential and further these activities were confirmed with the help of molecular docking study.

Non-toxic nature of chebulinic acid on biochemical, hematological and histopathological analysis in normal Sprague Dawley rats.

Chebulinic acid (CA) is an ellagitannins isolated from the dried fruits of Terminalia chebula with diverse pharmacological activities. The present study focused on the acute toxicity of CA in normal Sprague Dawley (SD) rats. CA was administered via oral gavage to different groups in 300 and 2000 mg/kg body weight and vehicle respectively. All the animals were monitored carefully for any physiological or behavioral changes for 14 days. On day 15th animals were euthanized and blood was collected for hematological and biochemical analysis. Different tissues were collected for histopathological study using four different staining techniques (hematoxylin and eosin, Masson's trichrome, periodic acid Schiff and picro sirius red) to observe any pathological alterations. The results highlighted no morbidity and mortality after oral ingestion of CA (300 and 2000 mg/kg). Food and water consumption, body weight, relative organ weight, hematological and biochemical parameters were normal without any gross pathological lesions in harvested tissues. The outcome of the current study supported safety of CA even at high dose. However, further detailed study is required on experimentally disease model to unfold its therapeutic potential in laboratory animals.

Arjunolic acid downregulates elevated blood sugar and pro-inflammatory cytokines in streptozotocin (STZ)-nicotinamide induced type 2 diabetic rats.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a worldwide health issue primarily due to failure of pancreatic ß-cells to release sufficient insulin. PURPOSE: The present work aimed to assess the antidiabetic potential of arjunolic acid (AA) isolated from Terminalia arjuna in type 2 diabetic rats. STUDY DESIGN: After extraction, isolation and purification, AA was orally administered to type 2 diabetic Sprague Dawley rats to investigate antidiabetic effect of AA. METHOD: T2DM was induced via single intraperitoneal injection of streptozotocin-nicotinamide (STZ-NIC) in adult male rats. After 10 days, fasting and random blood glucose (FBG and RBG), body weight (BW), food and water intake, serum C-peptide, insulin and glycated hemoglobin (HbA1c) was measured to confirm T2DM development. Dose dependent effects of orally administered AA (25 and 50 mg/kg/day) for 4 weeks was investigated by measuring BW variation, fasting and postprandial hyperglycemia, oral glucose tolerance test (OGTT), and levels of serum HbA1c, serum total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), serum and pancreatic C-peptide, insulin, growth differentiation factor 15 (GDF-15), serum and pancreatic inflammatory cytokines. RESULTS: The oral administration of AA in preclinical model of T2DM significantly normalized FBG and RBG, restored BW, controlled polyphagia, polydipsia and glucose tolerance. In addition, AA notably reduced serum HbA1c, TC, TG, LDL with non-significant increase in HDL. On the other hand, significant increase in serum and pancreatic C-peptide and insulin was observed with AA treatment, while serum and pancreatic GDF-15 were non-significantly altered in AA treated diabetic rats. Moreover, AA showed dose dependent reduction in serum and pancreatic proinflammatory cytokines including TNF-α, IL-1ß and IL-6. CONCLUSION: For the first time our findings highlighted AA as a potential candidate in type 2 diabetic conditions.

Analyzing the linkage among CO2 emissions, economic growth, tourism, and energy consumption in the Asian economies.

The study empirically explores the long-run dynamic influence of output, tourism, energy use, trade, financial development, and urbanization on CO2 emissions in the framework of EKC for Asian economies for the time period 1995-2017. In this study, we tackle cross-sectional dependence problem and use CADF and CIPS unit root tests in contrast to conventional unit root tests. Moreover, we employ LM bootstrap panel co-integration test. The results of DOLS show that GDP and GDP squares have opposite signs which shows inverted u-shaped hypothesis between GDP growth and carbon emissions. We find an evidence of EKC proposition in case of Asian economies. Tourism has a vital role in increasing environment degradation of Asian economies as magnitude of coefficient is 0.132. Moreover, energy use, urbanization, trade, and financial development have direct and a profound impact on environmental degradation. The empirical results thus point to the fact that tourism, trade openness, and urbanization have contributed to the environmental degradation in the Asian region. Hence, the counties of the region should harness renewable energy sources along with environment-friendly technologies to support the tourism at a sustainable level that may be conducive to economic growth and environmental quality as well.

Lauric acid ameliorates lipopolysaccharide (LPS)-induced liver inflammation by mediating TLR4/MyD88 pathway in Sprague Dawley (SD) rats.

BACKGROUND: Lipopolysaccharide (LPS) is an endotoxin that leads to inflammation in many organs, including liver. It binds to pattern recognition receptors, that generally recognise pathogen expressed molecules to transduce signals that result in a multifaceted network of intracellular responses ending up in inflammation. Aim In this study, we used lauric acid (LA), a constituent abundantly found in coconut oil to determine its anti-inflammatory role in LPS-induced liver inflammation in Sprague Dawley (SD) rats. METHOD: Male SD rats were divided into five groups (n = 8), injected with LPS and thereafter treated with LA (50 and 100 mg/kg) or vehicle orally for 14 days. After fourteen days of LA treatment, all the groups were humanely killed to investigate biochemical parameters followed by pro-inflammatory cytokine markers; tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1ß. Moreover, liver tissues were harvested for histopathological studies and evaluation of targeted protein expression with western blot and localisation through immunohistochemistry (IHC). RESULTS: The study results showed that treatment of LA 50 and 100 mg/kg for 14 days were able to reduce the elevated level of pro-inflammatory cytokines, liver inflammation, and downregulated the expression of TLR4/NF-κB mediating proteins in liver tissues. CONCLUSION: These findings suggest that treatment of LA has a protective role against LPS-induced liver inflammation in rats, thus, warrants further in-depth investigation through mechanistic approaches in different study models.

Food additive "lauric acid" possess non-toxic profile on biochemical, haematological and histopathological studies in female Sprague Dawley (SD) rats.

BACKGROUND: Lauric acid (LA), a common constituent of coconut oil, is used as food additives and supplements in various formulations. Despite various potential pharmacological properties, no scientific evidence on its dose-related toxicity and safety is available till date. OBJECTIVE: The current study was conducted to evaluate acute oral toxicity of LA on normal rats. METHODS: The study was conducted in accordance with the Organization for Economic Co-operation and Development guidelines (OECD 423) with slight modifications. LA was administered orally to female Sprague Dawley (SD) rats (n = 6/group) at a single dose of 300 and 2,000 mg/kg body weight, respectively, while normal control received vehicle only. Animals from all the three groups were monitored for any behavioural and toxicological changes and mortality for two weeks. Food and fluid consumption, body weight was monitored on daily basis. At the end (on day 15th) of the experimental period, blood was collected for haematological and biochemical analysis. Further, all the animals were euthanized, and internal organs were harvested for histopathological investigation using four different stainings; haematoxylin and eosin, Masson trichrome, Periodic Acid Schiff and Picro Sirius Red for gross pathology through microscopical observation. RESULTS: The study results showed no LA treatment-related mortality and morbidity at two different dosages. Daily food and water consumption, body weight, relative organ weight, haematological, and biochemical analysis were observed to be normal with no severe alterations to the internal tissues. CONCLUSION: The current finding suggests that single oral administration of LA, even up to 2,000 mg/kg body weight, did not exhibit any signs of toxicity in SD rats; thus, it was safe to be used on disease models in animals.

SAR based in-vitro anticholinesterase and molecular docking studies of nitrogenous progesterone derivatives.

Progesterone is a steroidal hormone that has been described with pathogenic features of brain dysfunction, realized with advanced age-related neurodegenerative diseases such as Alzheimer's disease. In this study, sixteen nitrogenous derivatives of progesterone which we previously synthesized have been used for Alzheimer targets. The progesterone derivatives (1-16) were screened for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory potentials in a dose-dependent manner. All the compounds exhibited overwhelming AChE inhibitions, with IC50 values ranging from 14.40 to 40.37 µM. Similarly, the BChE inhibitory potentials of our compounds were also dominant with IC50values between 20.08 and 46.84 µM. In comparison to our compounds, the standard drug galantamine attain IC50 values of 12.03 and 18.20 µM against AChE and BChE respectively. Molecular docking studies suggested that the compounds exerted their inhibitory activity by binding to the active site of the enzyme. The cholinergic system plays an important role in the regulation of learning and memory processes and has been a major target for the design of anti-Alzheimer's drugs. Therefore, these nitrogen-containing progesterone derivatives will be of potential interest to researchers working in AD for developing new drugs or chemical tools to study the disease.

Wnt signaling mediates TLR pathway and promote unrestrained adipogenesis and metaflammation: Therapeutic targets for obesity and type 2 diabetes.

Diabesity is the combination of type 2 diabetes and obesity characterized by chronic low-grade inflammation. The Wnt signaling act as an evolutionary pathway playing crucial role in regulating cellular homeostasis and energy balance from hypothalamus to metabolic organs. Aberrant activity of certain appendages in the canonical and non-canonical Wnt system deregulates metabolism and leads to adipose tissue expansion, this key event initiates metabolic stress causing metaflammation and obesity. Metaflammation induced obesity initiates abnormal development of adipocytes mediating through the non-canonical Wnt signaling inhibition of canonical Wnt pathway to fan the flames of adipogenesis. Moreover, activation of toll like receptor (TLR)-4 signaling in metabolic stress invites immune cells to release pro-inflammatory cytokines for recruitment of macrophages in adipose tissues, further causes polarization of macrophages into M1(classically activated) and M2 (alternatively activated) subtypes. These events end with chronic low-grade inflammation which interferes with insulin signaling in metabolic tissues to develop type 2 diabetes. However, there is a dearth in understanding the exact mechanism of Wnt-TLR axis during diabesity. This review dissects the molecular facets of Wnt and TLRs that modulates cellular components during diabesity and provides current progress, challenges and alternative therapeutic strategies at preclinical and clinical level.

Oral toxicity of arjunolic acid on hematological, biochemical and histopathological investigations in female Sprague Dawley rats.

BACKGROUND: Arjunolic acid (AA) is a potent phytochemical with wider pharmacological activities. Despite potential medicinal properties on various in vitro and in vivo studies, there is still a dearth of scientific data related to its safety profile and toxicological parameters. The current study aimed to investigate acute toxicity of AA in normal female Sprague Dawley rats. METHODS: In this study, AA was administered orally at an individual dose of 300 and 2000 mg/kg body weight to group 1 and 2 respectively, while group 3 served as normal control. All the animals were observed for 2 weeks to determine any behavioral and physical changes. On day 15, blood was collected for hematological and biochemical investigation, later animals from all the three groups were euthanized to harvest and store essential organs for histopathological analysis. Four different staining techniques; hematoxylin and eosin, Masson trichrome, Periodic acid Schiff and Oil O Red were used to investigate any alterations in different tissues through microscopical observation. RESULTS: The results of the study showed no morbidity and mortality at two different dosage of AA treatment. Daily food & water intake, body weight, relative organ weight, hematological and biochemical parameters were detected to be normal with no severe alteration seen through microscopical investigation in the structure of harvested tissues. Our findings support the safety profile of AA, which was well tolerated at higher dose. Thus, an in-detail study on the subacute disease model is warranted.

Self-assembly and wetting properties of gold nanorod-CTAB molecules on HOPG.

The formation of self-assembled superstructures of cetyltrimethylammonium bromide (CTAB) after drying on a nonwetting highly ordered pyrolytic graphite (HOPG) surface have been investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Although SEM did not reveal coverage of CTAB layers, AFM showed not only CTAB assembly, but also the dynamics of the process on the surface. The self-assembled layers of CTAB molecules on the HOPG terraces prior to nanorod deposition were shown to change the wettability of the surface, and as a result, gold nanorod deposition takes place on nonwetting HOPG terraces.

Role of oxidative stress in pathology of chronic prostatitis/chronic pelvic pain syndrome and male infertility and antioxidants function in ameliorating oxidative stress.

Oxidative stress (OS) is a result of the imbalance between reactive oxygen species (ROS) and antioxidants in the body that can cause tissue damage. Oxidative stress has a significant involvement in the pathogenesis of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and male infertility. CP/CPPS is a major risk factor for male infertility due to generation of excessive ROS that damage sperm DNA, lipids, and proteins, resulting in compromised vitality and decreased sperm motility. Here we present a comprehensive review of oxidative stress relevance in CP/CPPS and male infertility, and embody the protective effects of antioxidants against ROS. An online literature was searched using the following keywords/terms: oxidative stress, ROS, Oxidative stress and chronic prostatitis, oxidative stress and male infertility and antioxidants. Original and review articles, clinical trials, and case reports of human and animal studies published till 2017 were searched using the PubMed and MEDLINE.

Synthesis, pharmacological evaluation and docking studies of progesterone and testosterone derivatives as anticancer agents.

Steroidal hormones progesterone and testosterone play a vital role in breast and prostate cancers. In this research, we have synthesized and characterized a total of thirty-one (31) new nitrogenous derivatives of progesterone and testosterone. The synthesized derivatives (1-31) were screened for their anti-cancer potential against MCF-7 and PC-3 cell lines of breast using MTT assay. The compounds 1-31exhibited significant inhibitory potentials against MCF-7 and PC-3 cell lines. In MCF-7 assay, compound 17 displayed IC50 value of 04 ±â€¯0.02 µM while compound 18 was leading in PC-3 assay with IC50 of 03.14 ±â€¯0.4 µM. Tamoxifen was used as positive control which exhibited an IC50of 0.12 ±â€¯0.03 and 0.26 ±â€¯0.01 µM against MCF-7 and PC-3 respectively. The compounds also showed good anti-inflammatory activity according to oxidative burst inhibition by chemiluminescence technique where ibuprofen was used as positive control with 73.2 ±â€¯1.4% ROS inhibition. The compounds showed the percent ROS inhibition between 23.2 ±â€¯0.2 and -3.2 ±â€¯4.1. The results of the compounds were compared with the positive control ibuprofen. Molecular docking correlations suggest that the compounds exerted their inhibitory activity by binding to the active of the enzyme.

Norditerpenoid alkaloids of Delphinium denudatum as cholinesterase inhibitors.

Three new norditerpenoids alkaloids, 1ß-hydroxy,14ß-acetyl condelphine (1), jadwarine-A (2), jadwarine-B (3) along with two known alkaloids isotalatizidine hydrate (4) and dihydropentagynine (5) were isolated from medicinal plant Delphinium denudatum. The structures of natural products 1-5 were established on the basis of HR-EIMS, 1H and 13C NMR (1D & 2D) spectroscopic data as well as by comparison from literature data. The structures of compound 1 and 4 were also confirmed by single crystal X-ray diffraction studies. In-vitro AChE and BChE enzyme inhibitory activities of compounds 1-5 and molecular docking studies were performed to investigate the possible molecular inhibitory mechanism of the isolated natural products. Compound 2, 4 and 5 showed competitive inhibitory effects by inhibiting AChE and BChE, respectively, while 1 and 3 showed non-competitive inhibition. This work is the first report that provides a supporting evidence about the use of constituents of Delphinium denudatum in cerebral dementia and Alzheimer diseases.

Selective dual cholinesterase inhibitors from Aconitum laeve.

New lycoctonine-type dual cholinesterase inhibitor, swatinine-C (1), along with three known norditerpenoid alkaloids, hohenackerine (2), aconorine (5) and lappaconitine (6) and two synthetically known but phytochemically new benzene derivatives, methyl 2-acetamidobenzoate (3) and methyl 4-[2-(methoxycarbonyl)anilino]-4-oxobutanoate (4), was isolated from the roots of A. laeve. Structures of new and known compounds (1-6) were established on the basis of latest spectroscopic techniques and by close comparison with the data available in literature. In vitro, compounds (1-6) were tested against AChE and BChE inhibitory activities. Compounds 1 and 2 showed competitive inhibition against AChE (IC50 = 3.7 µM, 4.53 µM) and BChE (IC50 = 12.23 µM, 9.94 µM), respectively. Compounds 5 and 6 showed promising noncompetitive type of inhibitory profile against AChE (IC50 = 2.51 and 6.13 µM) only. Compounds 3 and 4 showed weak inhibitory profile against both AChE and BChE.

Comprehensive overview of prostatitis.

Prostatitis is a common urinary tract syndrome that many doctors find problematic to treat effectively. It is the third most commonly found urinary tract disease in men after prostate cancer and Benign Prostate Hyperplasia (BPH). Prostatitis may account for 25% of all office visits made to the urological clinics complaining about the genital and urinary systems all over the world. In the present study, we classified prostatitis and comprehensively elaborated the etiology, pathogenesis, diagnosis, and treatment of acute bacterial prostatitis (category I), chronic bacterial prostatitis (category II), chronic pelvic pain syndrome (CPPS) (category III), and asymptomatic prostatitis (category IV). In addition, we also tried to get some insights about other types of prostatitis-like fungal, viral and gonococcal prostatitis. The aim of this review is to present the detail current perspective of prostatitis in a single review. To the best of our knowledge currently, there is not a single comprehensive review, which can completely elaborate this important topic in an effective way. Furthermore, this review will provide a solid platform to conduct future studies on different aspects such as risk factors, mechanism of pathogenesis, proper diagnosis, and rational treatment plans for fungal, viral, and gonococcal prostatitis.

Weak two-photon absorption applied to the rapid prototyping of cell scaffolds.

Two-photon polymerization (TPP) has been employed to generate deep structures using the biocompatible and optically transparent monomer ethoxylated bisphenol A dimethacrylate (EO=6) (EBPADMA) and 4, 4'-Bis(diethylamino)benzophenon as the photoinitiator. The two-photon absorption cross section of the initiator was measured to be 1 GM (1 GM=1×10(-50) cm(4) s photon(-1)) in EBPADMA. Here we have explored a weak absorption regime whereby deep structures (∼300 µm) can be generated in a single pass. This allows rapid fabrication of structures suitable for cell scaffolds where the length scales are small, ∼10 µm, but are required over long ranges, ∼cm. The dependence of the TPP properties on the writing power, speed, exposure time and NA, of the focusing lens were studied in detail. Diffraction calculations for the focusing optics employed show that spherical aberration plays a significant role in determining the feature sizes achieved.