17 research outputs found
Electroactive gellan gum/polyaniline spongy-like hydrogels
No full texthe ability of electroactive materials to influence and modulate cell behavior has been revealing great potential, especially in the field of skeletal muscle tissue engineering. Herein, we propose PANi-GG electroactive spongy-like hydrogels as potential materials to modulate myoblast bioresponse. polyaniline (PANi) adds electroconductiviy to gellan gum (GG) spongy-like hydrogels that hold a high resemblance to the extracellular matrix (ECM), that is, water content, mechanical properties, and microarchitecture, and that can be further tuned to meet muscle tissue properties. For this purpose, PANi-GG spongy-like hydrogels were obtained by ionically cross-linking with calcium chloride (CaCl2) and further in situ aniline polymerization through oxidation with ammonium persulfate (APS) in a molar ratio of 1:1.05. The physicochemical characterization, surface morphology, electro-conductivity, and mechanical performance were assessed by FTIR, SEM, four-point probe technique, and compression testing, respectively. The viability and proliferation of L929 was not compromised after direct contact of PANi-GG spongy-like hydrogels with L929 cells, as determined by MTS assay and DNA quantification, respectively. C2C12 myoblasts were entrapped within the electroactive materials and cells adhered and spread. Moreover, cells proliferated along the cell culture period showing myosin expression after 7 days of culture. These results highlight that PANi-GG spongy like hydrogels are attractive candidates to be used in skeleton muscle tissue engineering.The authors gratefully thank Prof. Elvira Fortunato for the electrical conductivity measurement and
Alessandra Zonari for confocal microscopy. Pathomthat Srisuk was financially supported by Khon
Kaen University, Thailand. Fernanda V. Berti was supported by the grant of National Council for
Scientific and Technological Development (CNPq) of Brazil through the program Science without
borders and Lucília P. da Silva was financially supported by Fundação para a Ciência e Tecnologia
(FCT, SFRH/BD/78025/2011). The FCT fellowship distinction attributed to Vitor M. Correlo
under the Investigator FCT program (IF/01214/2014) is also greatly acknowledged.
Pageinfo:eu-repo/semantics/publishedVersio
Exploitation of natural eumelanin and conductive polymers on the preparation of electroactive systems for skeletal muscle tissue engineering applications
No full textTese de Doutoramento em Engenharia de Tecidos, Medicina Regenerativa e Células EstaminaisSkeletal muscle tissues comprise about 40-45% of the total human body mass. The skeletal muscle
functionality is commonly depreciated as a consequence of congenital abnormalities, traumatic
injuries from accidents or sports activities, and neurological diseases. The defects in muscle structure
can affect the physiological performance of the body as a whole, which further influences the
psychological responses. It has been demonstrated that electrical stimulus can affect cell behavior,
namely, adhesion, proliferation and differentiation and accelerate the healing of damaged tissues like
bone and nerves. Moreover, electrical stimulation is one of the emerging tools being used in clinics
with the purpose of inducing and recovering the physiological functionality in damaged muscle tissues.
However, the clinical outcomes are limited to the specific local area, such as head, legs, arms and
back.
Despite the intrinsic capacity of skeletal muscle tissues to self-repair, in case of severe tissue damage
or loss, such capacity is insufficient to restore the functionality. The conventional clinical treatment
modalities include allocation of autologous muscle by surgical treatment, but clinical outcomes are
not very satisfactory. Thus, by combining the advantages of electrical stimulus, including cell fate
modulation, with electroactive materials and tissue engineering approaches, we expect to overcome
some of the existing limitations. Indeed, skeletal muscle tissue engineering holds great potential to
alleviate the increasing burden of defective muscle tissues by constructing viable substitutes for
replacement therapies. Nevertheless, the reconstruction of tissue engineered skeletal muscle
substitutes should mimic native skeletal muscle-like structural properties including myofibers
uniformity and density throughout the functional muscle cells.
This thesis is focus on the exploitation of novel biomaterials, in particular, natural and synthetic
polymers, with electrical properties, for skeletal muscle tissue engineering applications. Eumelanin
from Sepia ink (Sepia officinalis) was initially purified by a well-established protocol and analyzed by
colorimetric oxidative assay for investigating the redox activity. To explore intrinsic properties of
eumelanin nanoparticles and expand its applications, an innovative approach was developed, which
consisted in the preparation of electrospun PVA nanofibers meshes containing eumelanin
nanoparticles. The physical properties, in particular, electrical conductivity, and biological performance
of the nanofibrous meshes were significantly improved upon eumelanin incorporation, indicating that
EUNp-PVA nanofibrous matrices are excellent candidates to be used in skeletal muscle tissue
engineering applications. In parallel, novel electroactive spongy-like hydrogels were developed by
combining gellan gum (GG) with two different conductive synthetic polymers: polypyrrole (PPy) and polyaniline (PANi). GG is a linear anionic polysaccharide of natural origin that has been extensively
studied for a wide range of biomedical applications and can be transformed in a hydrogel at body
temperature by ionic crosslinking. When processed as spongy-like hydrogels, these materials retain
the structural features of hydrogels relevant for tissue engineering applications and improved
mechanical and cell adhesive properties. Thus, the rationale behind adding synthetic conducting
polymers, PPy and PANi, was to improve the electroconductive properties of the final constructs,
maintaining simultaneously the improved mechanical features and intrinsic cell-adhesive ability of GG
spongy-like hydrogels. The physical, chemical and electrical properties were analyzed, and cytotoxicity,
as well as, biocompatibility was assessed both in vitro and in vivo. Both PPy-GG and PANi-GG
electroactive spongy-like hydrogels have shown high porosity and interconnected pores, showing
enhanced cellular response during in vitro studies. Moreover, negligible inflammatory response was
observed during in vivo analysis. The results demonstrate that the electroactive PPy-GG and PANi-GG
spongy-like hydrogels meet all the functional requirements for mimicking the ECM microenvironment
of muscle tissue, being interesting candidates to be used in skeletal muscle tissue regeneration
strategies.
The results reported in this thesis demonstrate the successful fabrication of eumelanin nanoparticlesincorporated
PVA nanofibrous meshes by electrospinning, as well as, the production of electroactive
PPy-GG and PANi-GG spongy-like hydrogels. Furthermore, physicochemical and biological assessment
of these three different matrices prove that these biomaterials have beneficial properties to be
employed in the development of tissue engineering strategies for the regeneration of skeletal muscle
tissues or other tissues of interest that respond favorably to electrical stimulation.O tecido muscular esquelético constituí cerca de 40-45% da massa total do corpo humano. A
funcionalidade do tecido muscular esquelético é frequentemente comprometida como consequência
de anomalias congénitas, lesões traumáticas decorrentes de acidentes ou atividades desportivas e
doenças neurológicas. Os defeitos no músculo-esquelético podem afetar o desempenho fisiológico do
corpo, influenciando as suas respostas fisiológicas. Foi demonstrado que o estímulo elétrico pode
afetar a comportamento celular, nomeadamente a adesão, proliferação e diferenciação, e acelerar a
cura dos tecidos danificados como os ossos e os nervos. Apesar da estimulação elétrica ser uma
ferramenta emergente usada na prática clínica com o objetivo de induzir e recuperar a funcionalidade
fisiológica dos tecidos danificados, os resultados clínicos são limitados a uma área específica como
cabeça, perna, braço e costas.
Apesar da capacidade intrínseca do músculo-esquelético para auto-reparação, em casos de danos
severos ou perda do tecido, essa capacidade é insuficiente para restaurar a funcionalidade do
músculo. As modalidades de tratamento clínico convencionais incluem alocação de músculo autólogo
por tratamento cirúrgico, no entanto, os resultados clínicos não são muito satisfatórios. Assim, através
da combinação das vantagens do estímulo elétrico com materiais electrocondutores e engenharia de
tecidos, pretendemos ultrapassar algumas das limitações existentes na regeneração do músculoesquelético.
De facto, a engenharia de tecidos do músculo-esquelético apresenta grande potencial
para reduzir a elevada percentagem de tecidos musculares defeituosos através da construção de
substitutos viáveis para terapias de reposição. No entanto, a reconstrução do tecido fabricado pela
engenharia de tecidos deve simular o tecido muscular nativo nas suas propriedades estruturais,
incluindo a uniformidade e densidade das células musculares.
Esta tese foca-se na exploração de novos biomateriais, em particular, polímeros materiais e sintéticos,
com propriedades elétricas, para a engenharia de tecido muscular esquelético. A eumelaninn da Sepia
ink (Sepia officinalis) foi inicialmente purificada por um protocolo estabelecido e analisada por um
ensaio colorimétrico oxidativo para investigar as suas propriedades oxidativas/redutoras.
Para explorar as propriedades intrínsecas das nanopartículas de eumelanina e alargar as suas
aplicações, uma nova abordagem foi desenvolvida, que consistiu na preparação de nanofibras de PVA
por “electrospun” contendo na malha das fibras nanopartículas de eumelanina. As propriedades
físicas, em particular a condutividade e o desempenho biológico das malhas de nanofibras foram
melhoradas significativamente após a incorporação de eumelanina, indicando que as matrizes de
nanofibras de eumelanina nanopartícula-álcool polivinílico (EUNp-PVA) são excelentes para serem
usadas em engenharia de tecidos do tecido muscular esquelético. Em paralelo, novos hidrogéis “spongy-like” foram desenvolvidos com gellan gum (GG) com dois
polímeros condutores diferentes: polypyrrole (PPy) e polianilina (PANi). Gellan gum é um
polissacarídeo aniónico linear cuja origem natural tem sido intensamente estudada para vasto número
de aplicações biomédicas, que pode ser transformado num hidrogel à temperatura do corpo por
reticulação iónica. Quando processado como um “spongy-like” hidrogel, retém as estruturas
estruturais dos hidrogéis relevantes para engenharia de tecidos e melhoram as propriedades
mecânicas e de adesão das células. Assim, o objetivo de adicionar polímeros condutores sintéticos,
PPy and PANi, foi o de melhorar as propriedades electrocondutoras dos construtos finais, mantendo
simultaneamente as características mecânicas e de adesão celular dos “spongy-like” GG hidrogéis.
As propriedades físicas, químicas e elétricas foram analisadas, e a citoxicidade, assim como a
biocompatibilidade foi avaliada in vitro e in vivo. Ambos “spongy-like” hidrogéis PPy-GG e PANi-GG
apresentam grande porosidade e poros interconectados. Demonstrando assim melhor resposta
celular durante os estudos in vitro. No entanto, inflamação celular não significativa foi detetada
durante os estudos in vivo. Os resultados demonstram que os hidrogéis eletroactivos “spongy-like”
PPy-GG e PANi-GG preenchem todos os requisitos funcionais para substituir a matriz extracelular
(ECM) do tecido muscular, sendo candidatos interessantes para serem utilizados nas estratégias de
regeneração do tecido muscular esquelético.
Os resultados desta tese demostram a fabricação de nanopartículas de eumelanin e a sua
incorparação em malhas de nanofibras à base de PVA produzidas por electrospinning, assim como a
produção de hidrogéis “spongy-like” condutores. A avaliação físico-química e biológica destas 3
matrizes diferentes prova que estes biomateriais têm propriedades beneficiais para serem utilizados
no desenvolvimento de estratégias de engenharia de tecidos para a regeneração do músculo
esquelético ou outros tecidos de interesse que respondem favoravelmente à estimulação elétrica
Natural based eumelanin nanoparticles functionalization and preliminary evaluation as carrier for gentamicin
No full textPurpose of the work was to modified natural based eumelanin nanoparticles surface by dopamine selfpolymerization
(FEUNp), facilitating conjugation through polydopamine bioactive functional groups and
improving nanoparticle surface hydrophilicity. SEM, TEM, and AFM characterization confirmed FEUNp
spherical shape (230.04 ± 8.25 nm) and their polydopamine coating. Individual indole or indoline structure
spectrum at 1600 cm−1 and C:N mass 9.08 was highlighted by FTIR and XPS analysis respectively. Quartzcrystal
microbalance with dissipation monitoring (QCM-D) and thermal gravimetric analysis (TGA) showed
successful polydopamine adsorption to eumelanin nanoparticles surface, a weight ratio of eumelanin nanoparticles/dopamine
of 1/2.46 in the wet state and 1/0.20 in the dry state; the −36.60 ± 0.45 mV negatively
surface charges confirms the presence of PD covering. FEUNp were loaded with gentamicin sulfate, for application
in infectious diseases therapies, such as osteomyelitis. Nanoparticles drug entrapment efficiency
was 32.42 ± 3.21%, and ζ-potential close to neutrality (−1.84 ± 0.58 mV). FEUNp-GS antimicrobial effect
was tested on Staphylococcus aureus and Escherichia coli showing gentamicin 24 h sustained release from
FEUNp-GS. IC50 and IC90 were 110.60 μg/mL and 216.39 μg/mL against S. aureus, and 54.13 μg/mL and
101.25 μg/mL against E. coli. The results are promising for FEUNp-GS as delivery system potentially useful
diverse administration routes.The authors acknowledge the work was supported by the European
Union (Horizon 2020) funded project FoReCaST (n° 668983), FEDER
(n° 007038), through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the Project POCI-01-0145-FEDER-007038.
Alexandra G. Fraga was supported by the FCT fellowship SFRH/BPD/
112903/2015. Rui R. Costa acknowledges the financial support from
Fundação para a Ciência e Tecnologia (Grant SFRH/BPD/95446/2013), “Fundo Social Europeu” (FSE), and “Programa Operacional de Potencial
Humano” (POPH). The FCT fellowship distinction attributed to Vitor M.
Correlo under the Investigator FCT program (IF/01214/2014) is also
greatly acknowledged. We also thank Khon Kaen University, Thailand
for financial support to Pathomthat Srisuk.info:eu-repo/semantics/publishedVersio
การใช้แป้งข้าวเหนียวดัดแปรด้วยเทคนิคไมโครเวฟเป็นสารยึดเกาะในยาเม็ด Microwave-treated Glutinous Rice Starch as A Tablet Binder
No full textบทคัดย่อ วัตถุประสงค์: เพื่อศึกษาการใช้แป้งข้าวเหนียวที่ดัดแปรด้วยไมโครเวฟ (GRMi) เป็นสารยึดเกาะในการผลิตยาเม็ดที่เตรียมด้วยวิธีแกรนูลเปียก วิธีการศึกษา: เตรียมยาเม็ดด้วยวิธีแกรนูลเปียกที่ประกอบด้วยไมโครคริสทัลไลน์เซลลูโลส (MCC) หรือแลคโตสโมโนไฮเดรต (Lac) โดยใช้สารยึดเกาะในปริมาณร้อยละโดยน้ำหนักดังนี้ 1) ร้อยละ 0, 2) GRMi ร้อยละ 2.5 และ 3) แป้งข้าวเหนียวที่ให้ความร้อนโดยตรง (GRB) ร้อยละ 2.5 และใช้แมกนีเซียมสเตียเรตร้อยละ 1 โดยน้ำหนัก โดยตอกอัดยาเม็ดด้วยแรงที่ต่างกัน (40, 60 และ 80 kgf/cm2) แล้วประเมินสมบัติของยาเม็ด ผลการศึกษา: ยาเม็ดที่ใช้ MCC มีความต้านแรงอัดแตกในช่วง 9.52 - 17.72 kgf ซึ่งสูงกว่า Lac (1.10 - 5.98 kgf) เวลาในการแตกตัวและสภาพกร่อนของยาเม็ดที่ใช้ MCC อยู่ในช่วง 11.40 - 59.40 วินาที และร้อยละ 0.08 - 0.41 โดยน้ำหนัก ตามลำดับ ซึ่งต่ำกว่ายาเม็ดที่ใช้ Lac ที่อยู่ในช่วง 70.80 - 5,170.20 วินาที และร้อยละ 0.88 - 3.89 โดยน้ำหนัก ตามลำดับ และยังพบว่าการเพิ่มแรงตอกอัดทำให้ยาเม็ดมีค่าความต้านแรงอัดแตกและเวลาในการแตกตัวเพิ่มขึ้น แต่มีสภาพกร่อนลดลง เมื่อเพิ่มแรงอัดให้แก่ยาเม็ดที่ใช้สารยึดเกาะ GRMi และ GRB พบว่าสามารถทำให้ยาเม็ดมีค่าความแข็งแรง (CSFR) และดัชนีชี้วัดคุณภาพยาเม็ด (CSFR/DT index) เพิ่มมากขึ้นได้ แสดงถึงความสามารถในการยึดเกาะที่ดีและสมบัติการเป็นยาเม็ดที่ดีขึ้น สรุป: สามารถใช้แป้งข้าวเหนียวที่ดัดแปรด้วยไมโครเวฟเป็นสารยึดเกาะในการเตรียมยาเม็ดด้วยวิธีแกรนูลเปียกได้ คำสำคัญ: แป้งข้าวเหนียว, แป้งดัดแปรด้วยไมโครเวฟ, การเตรียมด้วยวิธีแกรนูลเปียก, สารยึดเกาะ Abstract Objective: To investigate microwave-treated glutinous rice starch (GRMi) used as a binder in wet granulation tablets. Methods: Being prepared with wet granulation method, each tablet consisted of filler (microcrystalline cellulose (MCC) or lactose monohydrate (Lac)), binder (0% w/w, 2.5% w/w of GRMi, or 2.5% w/w of heated glutinous rice starch (GRB)) and 1% w/w of magnesium stearate. All tablet formulations were compressed by various compression forces (40, 60, and 80 kgf/cm2) and tablet properties were evaluated. Results: The MCC-tablets had a crushing strength (CS) of 9.52-17.72 kgf. which was higher than that of Lac-tablets (1.10 - 5.98 kgf.). The disintegration time (DT) and friability (F) of MCC-tablets (11.40 - 59.40 sec and 0.08 - 0.41%, respectively) were lower than those of Lac-tablets (70.80 - 5,170.20 sec and 0.88 - 3.89%, respectively). The increase of compression force resulted in increased CS and DT and decreased F. When compression force was increased to tablets using GRMi and GRB as a binder, the higher crushing strength-friability ratio (CSFR) and crushing strength-friability/disintegration time ratio (CSFR/DT index) in both tablets were observed. These results indicated better binding capability with improved tablet properties. Conclusions: microwave-treated glutinous rice starch could be used as a binder in wet granulation tablets. Keywords: glutinous rice starch, microwave-treated starch, wet granulation method, binde
PREPARATION AND CHARACTERIZATION OF GRAPEFRUIT OIL BASE MICROEMULSIONS OF CAFFEINE
No full textObjective: The objective of the present work was to prepare and characterize grapefruit oil base microemulsions loaded with caffeine as a model hydrophilic compound.
Methods: The formulation ingredients were selected based on surfactant efficiency and solubility studies. Ternary phase diagrams of grapefruit oil were constructed using the water titration method. Nine O/W microemulsions were constructed and prepared by mixing surfactant system, grapefruit oil, water and caffeine together. The resulting microemulsions were investigated for viscosity using Brookfield viscometer, for pH value using a digital pH meter, and for average particle size and polydispersity index (PDI) using a Zetasizer Nano. Ex vivo skin permeation through porcine ear skin was conducted using a side-by-side diffusion cell. The amount of caffeine was analyzed using HPLC-UV method.
Results: Tween 20 yielded the highest emulsification ability for grapefruit oil and the highest caffeine solubility. It was selected as a major surfactant. Caffeine was slightly soluble in ethanol and isopropyl alcohol, but sparingly soluble in propylene glycol (PG). These ingredients were used as the cosurfactants. Nine grapefruit oil base microemulsions were prepared and characterized. The pH of microemulsions was within the range of 4.48-5.96. Particle size was in the range of 10.81±0.03 to 62.18±21.04 µm with the PDI of 0.13±0.02 to 0.64±0.11. Viscosity and particle size of microemulsions increased significantly with increasing grapefruit oil or tween 20 content. Addition of PG as cosurfactant resulted in the increases of viscosity, particle size and PDI. Depending on the formulation parameters, the permeation fluxes of caffeine from grapefruit oil base microemulsions were in the range of 28.4±3.4-361.4±15.2 µg/cm2/h.
Conclusion: The grapefruit oil base microemulsions were successfully formulated. The physical properties and caffeine permeation of these microemulsions were found to be dependent on the grapefruit oil content, tween 20 content, cosurfactant type and content, as well as caffeine loading. The optimal formulation of grapefruit oil base microemulsion suggested composition of 5% grapefruit oil, 50% surfactant system (tween 20 and ethanol at the ratio of 9:1), and water
Preparation and Evaluation of Alcohol-Alkaline-Treated Rice Starch as a Tablet Disintegrant
No full textPurpose: To prepare and characterize alcohol-alkaline modified rice starch (MRS) as a disintegrant for tablets.Methods: The preparation of MRS was carried out using 3 M NaOH and 40 % ethanol solution. Characterization carried out for MRS include morphology, swelling capacity, thermal and pasting properties. Direct-compressed tablets (DCT) containing either propranolol hydrochloride (PPNL) or hydrochlorothiazide (HCTZ) were evaluated for hardness, friability, disintegration time and drug release.Results: The microstructure of MRS was different in shape and dimension from that of rice starch (RS). The absence of gelatinization endotherm and FT-IR spectral peak for MRS correlated with change in MRS structure and arrangement. MRS showed significantly higher swelling capacity (p < 0.05) than RS, and also proved to be a disintegrant in DCT. The disintegration time of the tablets containing MRS was lower in the presence of large particles (3.55 ± 0.56 min); high content of MRS (1.03 ± 0.06 min); low content of lubricant (3.16 ± 0.44 min); water soluble filler (1.55 ± 0.16 min for Super-tab®); and model drug (0.84 ± 0.09 min for HCTZ) (p < 0.05).Conclusion: MRS exhibits improved water solubility and swelling capacity compared with RS, and is thus a good disintegrant for direct-compressed tablet formulations, especially in the presence of water insoluble fillers.Keywords: Rice starch, Alcohol-alkaline treatment, Disintegrant, Directly compressed tablet, Insoluble filler
A Multi-Stage Approach for Real Time Speed and Direction Estimations of Pedestrian
No full textAbstractIn autonomous vehicle system, the direction and speed of pedestrian must be estimated in order to guide the automatic breaking system. It can be used to protect the pedestrian walking on road. This paper presents a new algorithm for speed and direction estimations of pedestrian in real time. In the first step, the HOG features are extracted. The features are then fed to SVM for classification. Given the bounding box, the optical flow for each bounding box is calculated. Therefore, direction and speed are estimated from the optical flow. We achieved a very low time computation by using CPU-GPU co-design which is performed based on parallel processing. Experiments were performed to evaluate our system and compare several methods for time computation. Performance of our algorithm will also be demonstrated
Sodium Alginate-Quaternary Polymethacrylate Composites: Characterization of Dispersions and Calcium Ion Cross-Linked Gel Beads
No full textThe objective of this work was to examine the effect of quaternary polymethacrylate (QPM), a water-insoluble polymer with a positive charge, on the characteristics of the sodium alginate (SA) dispersions and the calcium alginate (CA) gel beads containing propranolol HCl (PPN). The SA-QPM composite dispersions presented the formation of flocculates with a negative charge due to the electrostatic interaction of both substances. The QPM addition did not affect the SA dispersions’ Newtonian flow, but the composite dispersions’ viscosity enhancement was found. The PPN-loaded CA-QPM gel beads had more spherical than the PPN-loaded CA gel beads. The incorporation of QPM caused a bigger particle size, higher drug entrapment efficiency, and greater particle strength of the gel beads. Despite the similar water uptake property, the PPN-loaded CA-QPM gel beads displayed lower burst release and slower drug release rate than the PPN-loaded CA gel beads. However, the drug release from the PPN-loaded CA-QPM gel beads involved drug diffusion and matrix swelling mechanisms. This study demonstrated that adding QPM into the SA dispersions leads to a viscosity synergism. The CA-QPM gel beads display a good potential for use as a bioactive compound delivery system
Curcuma sumonii sp. nov., and C. wanchaii sp. nov. (Zingiberaceae), two new taxa of Curcuma subgen. Curcuma from Thailand
No full textAbstract This research presents the discovery of two novel taxa, Curcuma sumonii Saensouk, P.Saensouk, Boonma & Techa, and C. wanchaii Saensouk, P.Saensouk, Maknoi & Boonma, belonging to the Curcuma subgenus Curcuma. Curcuma sumonii was collected in Sukhothai Province, Northern Thailand, while C. wanchaii was found in Kanchanaburi Province, Southwestern Thailand. Our study provides a comprehensive documentation of their morphological attributes, including detailed descriptions supported by visual aids. In addition to morphological data, we offer insights into vernacular names, ecological characteristics, phenology, traditional uses, conservation status, and distribution maps. Morphological comparison Tables 1 and 2 are provided to differentiate between these newly discovered taxa and their allied species. Furthermore, we present an identification key to facilitate the differentiation of these taxa from their allied species. The findings of this study contribute to the understanding of biodiversity within the Curcuma genus and offer valuable information for further conservation efforts and taxonomic research
Redox activity of melanin from the ink sac of Sepia officinalis by means of colorimetric oxidative assay
No full textThe redox properties of natural extract from cuttlefish ink sac (Sepia officinalis) and synthetic melanin used as a biomimetic in melanin structural investigation were determined by comparison of this phenol-based heterogeneous pigment with gallic acid used as a standard in Folinâ Ciocalteu colorimetric assay widely employed for characterisation of oxidative properties of biomaterials. Reactivity of sepia melanin reported here is much higher than previously indicated and this protocol should allow the redox characterisation of all melanins irrespective of their origin and composition.European Union’s Seventh Framework Programme (FP7/2007-2013) [grant agreement number REGPOT-CT2012-316331-POLARIS
