Capping Shell Research Articles

Improved-FSDT-based solid-shell element for buckling analysis of plate, spherical cap, and cylindrical shell of FG porous materials

This study's objective is to propose a full three-dimensional finite element modeling for examining the buckling behaviors of functionally graded (FG) porous materials with plates, spherical cap, and cylindrical shapes. An improved first-order shear deformation theory (IFSDT) is utilized in order to develop the three-dimensional solid-shell element. The governing equations are developed in a way that offers a parabolic distribution of the transverse shear strains through the FG porous shell thickness and a zero condition of the transverse shear stresses on the top and bottom surfaces. The given IFSDT solid-shell element has the ability to model any kind of shell structures and incorporates a three-dimensional material law. In this study, two types of porosity distribution functions are considered. The performance of the current IFSDT solid-shell element has been demonstrated by examining the buckling behavior of Functionally Graded Porous plates, spherical caps, and cylindrical shells. The effect of the porosity distribution, porosity coefficient, power-law index, geometrical design parameters and boundary conditions on the buckling behaviors of FG porous shells structures is evaluated.

Mycosynthesis of silver nanoparticles using psychrotrophic strains of Tulasnella albida Bourdot & Galzin from the South Orkney Islands (Antarctica)

This study is the first report on mycosynthesis of silver nanoparticles (NPs) using psychrotrophic Antarctic filamentous fungi, and the first report regarding Tulasnella (Basidiomycota). In this work, the ability to synthesize silver NPs from cell free filtrates of strains of Tulasnella albida isolated from Antarctica was assessed. All fungal filtrates were capable of synthesizing silver NPs with the addition of AgNO3. UV–vis spectroscopy, TEM and SEM microscopy analyses were performed to characterize the synthesized NPs. ATR-FTIR and Micro Raman spectroscopy analyses were conducted to find functional groups responsible for the reduction of AgNO3 and to detect the presence of silver oxide on the AgNPs. Theoretical calculations of optical absorption based on core-shell Ag–Ag2O were used to characterize the experimental absorption spectra of silver NPs colloids. Spherically shaped silver NPs, typically 2–3nm in diameter, were obtained. The largest ones showed a capping shell around them, which could be associated with the formation of small silver NPs. Functional groups corresponding to amides and alcohols were detected, confirming the presence of proteins as possible intermediates in the synthesis of AgNPs. On the other hand, the Micro Raman analysis confirms the presence of silver oxide on the surface of the AgNPs. This work presents a simple procedure for the synthesis of silver NPs using a psychrotrophic organism that could be interesting for the industry.

Effect of Ce3+ on the morphology, composition, and thermal properties of single and core-shell polyethylene oxide electrospun fibers

Cerium polymeric composites have novel applications in fuel cells, optical devices, gas sensors, catalysis, ultraviolet absorbers, hydrogen storage materials, and biomedicines. This study reports the fabrication of low-cost electrospun single and core-shell polyethylene oxide (PEO) doped with Cerium fibers fabricated in two moisture ambients. Scanning electron microscopy and atomic force microscopy revealed that obtaining the thinnest average fiber diameter requires 47-52 %RH and 2 % Cerium dopant. Using a PEO capping (shell fiber) allows the increment of Cerium in the inner matrix (core-fiber) to produce non-beading continuous fibers with 3.5% of the dopant. The undoped single or core-shell fibers presented a 52.7 to 54.2 % crystallinity, indecently of relative humidity used during the fabrication process. In contrast, the use of Cerium dopant up to 2% induces an increase in their crystallinity due to the formation of Ce-O species, enhancing their thermal properties, regardless of the moisture during manufacturing as was found with Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis.

Porous Mg‐stabilized amorphous calcium carbonate as carrier for hydrophobic drugs

AbstractIn this work, we demonstrate that porous MgACC microspheres could be prepared in liposome solution containing zwitterionic and anionic lipids. We find that the lipid molecules incorporated into MgACC could be as high as 10 mass%. Because hydrophobic drugs are lipophilic, the porous MgACC has been exploited as the carriers of hydrophobic drugs. Using lecithin as the source of lipids and N‐(rhodamine‐6G)lactam‐ethylenediamine (R6GNCCN) as the model of hydrophobic drugs, the optimal loading capacity was found to be ca. 1.4 mass%. The release of R6GNCCN to a phosphate buffer at pH 7.4 was over 90% within 5 hr. The drug release profile could be attenuated by encapsulating the MgACC core by a CaP shell.

Calcium Phosphorus Nanoparticles Coloaded with Paclitaxel and ADAM‐10‐siRNA for the Treatment of Triple Negative Breast Cancer

It is urgent to develop nonside effects and targeting and effective therapeutic agents for triple negative breast cancer (TNBC). Herein, first‐line chemotherapeutic drug paclitaxel (PTX) and a disintegrin and metalloproteinase 10 (ADAM10) small interfering RNA (siRNA) were simultaneously encapsulated in shell‐core‐distinct nanoparticles to enhance tumor suppressive effect. Specifically, copolymer DSPE‐PEG2K packed with PTX to form the hydrophobic core, while CaP shell coating siADAM10 to form the hydrophilic shell. The PEG chains in the outer layer of the nanoparticles prevent the immune system from engulfing them and thus increase their systemic circulation time. CaP‐PTX/siADAM10 NPs could target tumor site through the enhanced permeability and retention (EPR) effect. The siADAM10 in outer shell is first released to exert its gene inhibitory effect to increase the sensitivity of tumor cells to chemotherapeutic drugs, and then, the inner PTX is released from the CaP‐PTX/siADAM10 NPs to exert its tumor‐killing effect. The codelivery system of chemotherapeutic agent and siRNA in a core‐shell nanoparticle provided a potent effective cancer therapy.

METHOD OF CONTROLLING PRESENCE OF FOREIGN SUBSTANCES AND OBJECTS IN THE BORE OF THE BARREL USING MONOCHROME LIGHT

In the article, the authors propose a method for controlling the presence of foreign substances and objects inside the barrel. The problem of surface cleanliness control remains relevant in many areas, ranging from sanitary cleaning to nanoelectronics. In the military sphere, this becomes particularly important during the cleaning of cannon barrels. Both powder combustion products and cartridge cap and bullet shell particles are deposited in the barrel during firing from guns. Under the impact of high temperatures, the bullet particles are partially oxidized and cover the barrel channel with a thin layer of deposit of oxides, which are difficult to dissolve. As a result, the density of the bullet abuting the walls changes. This affects the characteristics of its motion inside the barrel. The accuracy of the shot is reduced, and subsequently the precision and accuracy of shooting in general decreases. The essence of the proposed method consists in the fact that a light source is placed in the bore of the barrel on one side, and an optical device is placed on the other side, with the help of which the presence of foreign substances and objects is monitored. Unlike the known methods, this method is characterized in that several monochrome light sources in addition are placed in turn in the bore of the barrel from the breech part, and in the bore of the barrel from the muzzle part there is equipment for receiving (detecting) monochrome light. Then, obtained monochrome light is analyzed, current value of its defined parameters is determined. At the next stage, parameter values of monochrome light fixed during control are compared with parameter values of reference signatures, which had been obtained before the barrel was put in service. These values are stored in equipment memory. If the values of at least one of the parameters from at least one of the monochrome light sources are found to be inconsistent with the parameters of the reference signatures, the equipment for receiving and analyzing monochrome light gives a signal about the presence of foreign substances and objects in the bore of the barrel.

A polymer‑calcium phosphate nanocapsule for RNAi-induced oxidative stress and cascaded chemotherapy

As most of intracellular reactive oxygen species (ROS) is produced in the mitochondria, mitochondrial modulation of cancer cell is a promising strategy for maximizing the in situ-activable combination therapy of oxidative catastrophe and cascaded chemotherapy. Herein, a serum-stable polymer‑calcium phosphate (CaP) hybrid nanocapsule carrying siRNA against ADP-ribosylation factor 6 (Arf6) overexpressed in cancer cells and parent drug camptothecin (CPT), designated as PTkCPT/siRNA, was developed for the RNAi-induced oxidative catastrophe and cascaded chemotherapy. A copolymer of mPEG-P(Asp-co-TkCPT), covalently tethered with chemotherapeutic CPT via a ROS-labile dithioketal (Tk) linker, was synthesized and self-assembled into a PTkCPT micelle as a nanotemplate for the CaP mineralization. The as-prepared PTkCPT/siRNA nanoparticle showed a core-shell-distinct nanocapsule which was consisted of a spherical polymeric core enclosed within a CaP shell capable of releasing siRNA in response to lysosomal acidity. Blocking Arf6 signal pathway of cancer cells led to their mitochondrial aggregation and subsequently induced a burst of ROS for oxidative catastrophe, which further triggered the cascaded CPT chemotherapy via the breakage of ROS-labile dithioketal linker. This strategy of RNAi-induced oxidative catastrophe and cascaded chemotherapy resulted in a significant combination effect on cancer cell killing and tumor growth inhibition in mice with low side effects, and provided a promising paradigm for precise cancer therapy.

Visualizing band alignment across 2D/3D perovskite heterointerfaces of solar cells with light-modulated scanning tunneling microscopy

Graded 2D perovskite capping shells with continuously upshifting valence bands, produced by tailored dimensional engineering, can effectively extract holes from 3D perovskite cores. Real-space observation of electronic structures will fully reveal the operating mechanisms of 2D/3D hybrid perovskite solar cells (PSCs). Here, for the first time, light-modulated scanning tunneling microscopy visualizes the cross-sectional band alignment across 2D (C 4 H 9 NH 3 ) 2 (CH 3 NH 3 ) n-1 Pb n I 3n+1 /3D CH 3 NH 3 PbI 3 stacked perovskites. By systematically analyzing their electronic configuration, the mixed-dimensional perovskite band structure along the vertical 3D-to-2D direction can be spatially resolved. Remarkably, the electric field in the 2D perovskite is larger under light illumination than under dark conditions, resulting in an increase in the concentration of holes and electrons distributed in the 2D and 3D perovskites, respectively. Benefiting from this electronic reconstruction, charge recombination is suppressed, thereby significantly promoting the 2D/3D PSC performance. Moreover, our method opens an avenue for direct, local mapping of optoelectronic device energy levels. • Real spacing energy band distribution of photo-activated 2D/3D perovskites is first mapped. • Visualization of photocarrier dynamics is demonstrated, promote efficiencies of 2D/3D perovskite solar cells. • The electric field in the 2D perovskite is enhanced under light illumination. • This LM-XSTM technology will be used for other semiconductor devices.

Natural frequency responses of hybrid polymer/carbon fiber/FG-GNP nanocomposites paraboloidal and hyperboloidal shells based on multiscale approaches

This paper is devoted to obtain the vibrational behavior of doubly curved shells with paraboloidal and hyperboloidal geometries using an efficient semi-analytical solution method. To obtain the governing differential equations of the shells, the First-order Shear Deformation Theory (FSDT) is used. In addition, the shell structure is composed of a new hybrid three phases nanocomposite material. The material includes three parts: (1) polymer matrix, (2) carbon macroscale fiber, and (3) Graphene NanoPlatelets (GNP) nanoscale filler. Three different multiscale approaches including (1) bridging model, (2) Mori-Tanaka scheme, and (3) generalized self-consistent model are employed for homogenization of hybrid matrix and macroscale carbon fibers. The governing equation of motions are obtained using Hamilton's principles and Green-Gauss theory. Afterwards, an efficient semi-analytical solution procedure entitled Generalized Differential Quadrature Method (GDQM) is used for solving the governing differential equations of the structure. Finally, the frequency parameter of the structure is achieved for different states of boundary conditions and geometric properties. Moreover, the results are verified with the responses of other references obtained for a paraboloidal (Cap) shell structure. It is worth mentioning that the effect of homogenization approach, boundary conditions, volume fraction of carbon fibers and distribution pattern of GNP within the polymer matrix are studied numerically. It is concluded that the solution method is accurate, efficient and capable to obtain the natural frequency of doubly curved shells.

Transformable Nanosensitizer with Tumor Microenvironment-Activated Sonodynamic Process and Calcium Release for Enhanced Cancer Immunotherapy.

Despite the promise of sonodynamic processes in cancer therapy, existing sonosensitizers often fail to regulate the generation of reactive oxygen species (ROS) against tumors, potentially leading to off-target toxicity to normal tissues. We report a transformable core-shell nanosonosensitizer (TiO2 @CaP) that reinvigorates ROS generation and dissolves its CaP shell to release Ca2+ in an acidic tumor microenvironment (TME) under ultrasound activation. Thus, TiO2 @CaP acts as a smart nanosonosensitizer that specifically induces mitochondrial dysfunction via overloading intracellular Ca2+ ions to synergize with the sonodynamic process in the TME. TiO2 @CaP substantially enhances immunogenic cell death, resulting in enhanced T-cell recruitment and infiltration into the immunogenic cold tumor (4T1). In conjunction with checkpoint blockade therapy (anti-PD 1), TiO2 @CaP-mediated sonodynamic therapy elicits systemic antitumor immunity, leading to regression of non-treated distant tumors and inhibition of lung metastasis. This work paves the way to development of "smart" TME-activatable sonosensitizers with temporospatial control over antitumor responses.

Transformable Nanosensitizer with Tumor Microenvironment‐Activated Sonodynamic Process and Calcium Release for Enhanced Cancer Immunotherapy

AbstractDespite the promise of sonodynamic processes in cancer therapy, existing sonosensitizers often fail to regulate the generation of reactive oxygen species (ROS) against tumors, potentially leading to off‐target toxicity to normal tissues. We report a transformable core‐shell nanosonosensitizer (TiO2@CaP) that reinvigorates ROS generation and dissolves its CaP shell to release Ca2+ in an acidic tumor microenvironment (TME) under ultrasound activation. Thus, TiO2@CaP acts as a smart nanosonosensitizer that specifically induces mitochondrial dysfunction via overloading intracellular Ca2+ ions to synergize with the sonodynamic process in the TME. TiO2@CaP substantially enhances immunogenic cell death, resulting in enhanced T‐cell recruitment and infiltration into the immunogenic cold tumor (4T1). In conjunction with checkpoint blockade therapy (anti‐PD 1), TiO2@CaP‐mediated sonodynamic therapy elicits systemic antitumor immunity, leading to regression of non‐treated distant tumors and inhibition of lung metastasis. This work paves the way to development of “smart” TME‐activatable sonosensitizers with temporospatial control over antitumor responses.

Dual stimuli-responsive polypeptide-calcium phosphate hybrid nanoparticles for co-delivery of multiple drugs in cancer therapy

In this study, a new type of polypeptide, crosslinked methoxy poly(ethylene glycol)-g-poly(aspartic acid)-g-tyrosine (CPPT), was synthesized via a green and simple one-pot polymerization method. With the disulfide-crosslinked interlayer and the CaP shell, the pH and redox dual-sensitive polypeptide-based organic-inorganic hybrid nanoparticles encapsulated curcumin (Cur) into the hydrophobic core of micelles and loaded doxorubicin hydrochloride (DOX) on the hydrophilic segment of micelles as well as CaP shell. The spherical Cur- and DOX-loaded nanoparticles (CPPT@CaP-CD) showed a hydrodynamics size of about 157.9 ± 3.9 nm. The premature leakage of drugs from the nanoparticles at physiological pH was efficiently restrained because of the enhanced structure integrity, whereas at acidic and hypoxia microenvironment the release of both drugs was promoted due to the rapid dissolution of the CaP shell and the break of the disulfide crosslinked network, facilitating the stimuli-responsive controllable drugs release. In vitro anticancer activity evaluation revealed that the co-loaded nanoparticles presented higher cytotoxicity against A549 cells compared with that of the free combination of Cur + DOX. Confocal laser scanning microscopy observation indicated that more DOX and Cur were released into the nucleus triggered by the up-regulated intracellular glutathione (GSH) concentration and decreased pH, displaying enhanced cell uptake. The self-assembling polypeptide-based dual-sensitive drug co-delivery system could be a promising platform for efficient chemotherapy.

Combined antioxidant capped and surface supported redox-sensitive nanoparticles for continuous elimination of multi-metallic species.

A strategic modification involving (i) a multi-functional almond shell biochar surface support and (ii) capping with almond skin extracted antioxidants was performed to preserve redox-sensitive Fe0 nanoparticles (NPs). pXRD data showed generation of an iron-carbonyl shell on the supported Fe0 NPs (SA-Fe0), justifying successful antioxidant capping. The total metal removal capacity of 695 mg g-1i.e. AsO2- (300.2 mg g-1) > Cd2+ (224.2 mg g-1) > CrO42- (125.2 mg g-1) > Ni2+ (44.5 mg g-1) in batch mode, and 102 mg g-1 in continuous column setup confirms the excellent reactivity of the SA-Fe0 nanocomposite. Loss of the iron-carbonyl shell and iron oxidation during interaction with contaminants confirm no hindrance in electron transfer due to antioxidant capping.

AZD9291 Resistance Reversal Activity of a pH-Sensitive Nanocarrier Dual-Loaded with Chloroquine and FGFR1 Inhibitor in NSCLC.

AZD9291 can effectively prolong survival of non‐small cell lung cancer (NSCLC) patients. Unfortunately, the mechanism of its acquired drug resistance is largely unknown. This study shows that autophagy and fibroblast growth factor receptor 1 signaling pathways are both activated in AZD9291 resistant NSCLC, and inhibition of them, respectively, by chloroquine (CQ) and PD173074 can synergistically reverse AZD9291 resistance. Herein, a coloaded CQ and PD173074 pH‐sensitive shell–core nanoparticles CP@NP‐cRGD is developed to reverse AZD9291 resistance in NSCLC. CP@NP‐cRGD has a high encapsulation rate and stability, and can effectively prevent the degradation of drugs in circulation process. CP@NP‐cRGD can target tumor cells by enhanced permeability and retention effect and the cRGD peptide. The pH‐sensitive CaP shell can realize lysosome escape and then release drugs successively. The combination of CP@NP‐cRGD and AZD9291 significantly induces a higher rate of apoptosis, more G0/G1 phase arrest, and reduces proliferation of resistant cell lines by downregulation of p‐ERK1/2 in vitro. CQ in CP@NP‐cRGD can block protective autophagy induced by both AZD9291 and PD173074. CP@NP‐cRGD combined with AZD9291 shows adequate tumor enrichment, low toxicity, and excellent antitumor effect in nude mice. It provides a novel multifunctional nanoparticle to overcome AZD9291 resistance for potential clinical applications.

Strongly luminescent and highly stable core-shell suprastructures from in-situ growth of CsPbBr3 perovskite nanocrystals in multidentate copolymer micelles

Lead halide perovskite nanocrystals (NCs) have shown exceptional optoelectronic characteristics and photovoltaic performance; however, their instability has limited their use in optoelectronic applications. Herein, we introduce a facile and effective in-situ synthesis strategy to prepare stable core-shell colloidal perovskite nanocrystal-polymer micelle composites (abbr. ap-POSS-PMMA-b-PDMAEMA@CsPbBr3) by using amphiphilic copolymer (abbr. ap-POSS-PMMA-b-PDMAEMA) self-assembled “reverse micelle” templates. The amphiphilic block copolymer with hydrophobic (ap-POSS and polymethylmethacrylate, PMMA) and hydrophilic blocks (poly 2-(dimethylamino)ethyl methacrylate, PDMAEMA) can be regulated to self-assemble into “reverse” micelles. The micelle serves as a confined nanoreactor during perovskite crystallization, which passivates the perovskite surface by forming a multidentate capping shell and yields the formation of multi-nanocubes with size between 6 and 8 nm and a photoluminescence quantum yield (PLQY) that surpasses 60%. Benefitting from femtosecond transient absorption (fs TA) and time-resolved photoluminescence (PL) spectroscopy studies, the excited carrier dynamics of the obtained composites substantiate fewer internal band-gap trap states from micelle-induced CsPbBr3 NCs. The films cast from these composites showed enhanced water-resistant properties as compared to bare NCs and previously reported encapsulated NCs. Therefore, the copolymer “reverse” micelle induced in-situ grown NCs provide a potential approach for further engineering the morphology of NC-based composites and open the door to potential scalable and robust optoelectronic applications.

Optical sensing of hydrogen peroxide using starch capped silver nanoparticles, synthesis, optimization and detection in urine

Silver nanoparticles were synthesized using starch as a capping shell, AgNO3 as a source of silver and sodium borohydride (NaBH4) as a reducing agent. The nanoparticles were confirmed by their localized surface plasmonic resonance (LSPR) Ultraviolet-visible (UV–Vis) absorbance at 403 nm. Dynamic light scattering (DLS) reveals that starch capped silver nanoparticles (SAgNPs) mean size were 4.13 nm/diameter; the structure of SAgNPs was identified as face-centered cubic (FCC) using XRD analysis. HRTEM micrograph and contrast intensity profile confirms Ag atomic lattices at a distance of 2.35 Å and 2.03 Å corresponding to (111) and (200) hkl plane. The scope of SAgNPs to detect hydrogen peroxide (H2O2) in aqueous media and in urine samples was investigated. Volumes of SAgNPs, pH, temperature and time effect were used as parameters to optimize the detection of H2O2. The SAgNPs assay was compared with a commercially available assay kit. Linear responses were obtained with slopes and regression factors of (0.1025; r2=0.9883) and (0.0776; r2=0.9940) for SAgNPs and the assay kit respectively. Limit of detection (LOD) of 3.70 µM was obtained in the 0.45–121 µM range while, a LOD of 10.5 nM was obtained in the 4.70–32.0 nM range for the SAgNPs test. Values in the range of (9.22 ± 0.30 – 17.89 ± 0.28) and (8.43 ± 0.06 – 26.81 ± 0.19) μM of H2O2 were assessed by using SAgNPs and assay kit respectively, in urine samples collected from seven apparently healthy men aged between 20 and 40 years old.

Analysis of Long-Term Deterioration Characteristics of High Voltage Insulators

The deterioration of the cement that bonds the cap, pin, and porcelain shell of the porcelain insulators can be observed by three-dimensional computed tomography (3D-CT), a non-destructive test. When porcelain insulators are used for a long duration, the size of the pores existing in the cement increase as the cement expands due to the alkali-silica reaction (ASR). It is possible to visually confirm the corrosion of caps and pins. The degree of corrosion is divided into four noticeable stages (I–IV), and deterioration of cement includes one of the four stages of corrosion. The standard time of replacement of insulator vs. continued use is presented. As a result of X-ray diffraction (XRD) analysis, Fe is oxidized to Fe2O3 at 36, 43, 54, and 70 degrees. The corrosion in cement is caused by factors including the value of pH, oxygen content, and temperature. For the caps and pins, although a zinc coating is applied to prevent the corrosion of iron, corrosion of zinc is caused by substances present in the external environment. When the zinc coating begins to corrode, the corrosion of the Fe component of the cap and pin accelerates, causing mechanical/electrical problems.

Determination of the size dispersion of amorphous silicon quantum dots from a silicon nitride film containing silicon nanocrystals

In this work we will investigate the size distribution of the amorphous silicon quantum dots (Si-AQD) inside a silicon nitride film SiNx (x = 0.12). The studied film contains an ensemble of silicon nanocrystals (Si-nc) inside an amorphous silicon nitride matrix SiNy (y = 0.66). Since the nitrogen atoms number are less than the silicon atoms number in the amorphous matrix, we can suggest that silicon atoms can aggregate under amorphous quantum dots. In this context, we will first estimate the number of crystallized silicon atoms (c-Si). The number of amorphous silicon atoms (a-Si) can be deduced from the fraction of crystallized silicon atoms and leads to the determination of the number of nitrogen atoms.Results show that all the nitrogen atoms are localized in the Si-ncs cap shell. Thus, the amorphous quantum dots can be easily revealed from the scattering electron microscopy (SEM) image. The low yield of luminescence from amorphous quantum dots can explain the difference between both experimental and simulated photoluminescence (PL) from silicon nitride film containing Si-ncs.

Core-Shell Biphasic Microspheres with Tunable Density of Shell Micropores Providing Tailorable Bone Regeneration.

We have developed the new core-shell bioceramic CSi-Sr4@CaP-px microspheres with tuning porous shell layer so that the biodegradation of both CSi-Sr4 core and CaP shell is readily adjusted synergistically. This is for the first time, to the best of our knowledge, that the bioceramic scaffolds concerning gradient distribution and microstructure-tailoring design is available for tailoring biodegradation and ion release (bioactivity) to optimizing osteogenesis. Furthermore, it is possibly helpful to develop new bioactive scaffold system for time-dependent tailoring bioactivity and microporous structure to significantly enhance bone regeneration and repair applications, especially in some non-load-bearing arbitrary 3D anatomical bone and teeth defects.

Gold nanoparticles synthesis assisted by marine algae extract: Biomolecules shells from a green chemistry approach

A “green” synthesis alternative for Au nanoparticles (NPs) is reported using an aqueous media, environmental friendly reducing agents and the replacement of alkytrimethylammonium halides by biocompatibles molecules. The usage of an extract from the alga Egregia sp. intrinsically provides with biomolecules for the shell formation around the Au NPs to aid for their biocompatibility. The detailed analysis presented here allows to elucidate the double role played by the algae extract as the reducing agent and as the stabilizing capping shell for the Au NPs colloid. The optimized parameters to obtain a narrow size distribution of Au NPs are elucidated.