A brief review on hydroxyapatite production and use in biomedicine

Abstract Hydroxyapatite (HAp) is a bioceramic widely studied due to its chemical similarity with the mineral component of bones. Besides, it is biocompatible, bioactive and thermodynamically stable in the body fluid what poses it as an attractive material for a wide range of applications in the biomedical field. Several efforts have been focused on the synthesis of particles of this material aiming to the precise control of size and morphology, porosity and surface area. HAp is widely used as an implant for bone tissue regeneration, as a coating for metallic implants and in a drug-controlled release. In this sense, the objective of this review is to gather information related to HAp, providing readers with information about synthesis methods, material characteristics and their applications.

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The Role of Zwitterionic Materials in the Fight against Proteins and Bacteria

Medicines ◽

10.3390/medicines5040125 ◽

2018 ◽

Vol 5 (4) ◽

pp. 125 ◽

Cited By ~ 8

Author(s):

Montserrat Colilla ◽

Isabel Izquierdo-Barba ◽

María Vallet-Regí

Keyword(s):

Tissue Regeneration ◽

Bone Tissue Regeneration ◽

Local Drug Delivery ◽

Clinical Use ◽

Metallic Implants ◽

Specific Proteins ◽

Biomedical Field ◽

Advanced Biomaterials ◽

Major Progress

Zwitterionization of biomaterials has been heightened to a potent tool to develop biocompatible materials that are able to inhibit bacterial and non-specific proteins adhesion. This constitutes a major progress in the biomedical field. This manuscript overviews the main functionalization strategies that have been reported up to date to design and develop these advanced biomaterials. On this regard, the recent research efforts that were dedicated to provide their surface of zwitterionic nature are summarized by classifying biomaterials in two main groups. First, we centre on biomaterials in clinical use, concretely bioceramics, and metallic implants. Finally, we revise emerging nanostructured biomaterials, which are receiving growing attention due to their multifunctionality and versatility mainly in the local drug delivery and bone tissue regeneration scenarios.

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The Potential Biomedical Application of NiCu Magnetic Nanoparticles

Magnetochemistry ◽

10.3390/magnetochemistry5040066 ◽

2019 ◽

Vol 5 (4) ◽

pp. 66 ◽

Cited By ~ 1

Author(s):

Janja Stergar ◽

Irena Ban ◽

Uroš Maver

Keyword(s):

Magnetic Nanoparticles ◽

Biomedical Applications ◽

The Body ◽

Target Site ◽

Annual Number ◽

General Interest ◽

Cancer Tissue ◽

Synthesis Methods ◽

Advantages And Disadvantages ◽

Wide Range

Magnetic nanoparticles became increasingly interesting in recent years as a result of their tailorable size-dependent properties, which enable their use in a wide range of applications. One of their emerging applications is biomedicine; in particular, bimetallic nickel/copper magnetic nanoparticles (NiCu MNPs) are gaining momentum as a consequence of their unique properties that are suitable for biomedicine. These characteristics include stability in various chemical environments, proven biocompatibility with various cell types, and tunable magnetic properties that can be adjusted by changing synthesis parameters. Despite the obvious potential of NiCu MNPs for biomedical applications, the general interest in their use for this purpose is rather low. Nevertheless, the steadily increasing annual number of related papers shows that increasingly more researchers in the biomedical field are studying this interesting formulation. As with other MNPs, NiCu-based formulations were examined for their application in magnetic hyperthermia (MH) as one of their main potential uses in clinics. MH is a treatment method in which cancer tissue is selectively heated through the localization of MNPs at the target site in an alternating magnetic field (AMF). This heating destroys cancer cells only since they are less equipped to withstand temperatures above 43 °C, whereas this temperature is not critical for healthy tissue. Superparamagnetic particles (e.g., NiCu MNPs) generate heat by relaxation losses under an AMF. In addition to MH in cancer treatment, which might be their most beneficial potential use in biomedicine, the properties of NiCu MNPs can be leveraged for several other applications, such as controlled drug delivery and prolonged localization at a desired target site in the body. After a short introduction that covers the general properties of NiCu MNPs, this review explores different synthesis methods, along with their main advantages and disadvantages, potential surface modification approaches, and their potential in biomedical applications, such as MH, multimodal cancer therapy, MH implants, antibacterial activity, and dentistry.

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A Review on the Green Synthesis of Silver Nanoparticles and Their Morphologies Studied via TEM

Advances in Materials Science and Engineering ◽

10.1155/2015/682749 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 65

Author(s):

Protima Rauwel ◽

Siim Küünal ◽

Stanislav Ferdov ◽

Erwan Rauwel

Keyword(s):

Green Synthesis ◽

Raw Materials ◽

Synthesis Methods ◽

Synthesis Of Nanoparticles ◽

Wide Range ◽

Methods Of Synthesis ◽

Size And Morphology ◽

Ecological Methods ◽

The Cost ◽

By Products

Silver has been recognized as a nontoxic, safe inorganic antibacterial/antifungal agent used for centuries. Silver demonstrates a very high potential in a wide range of biological applications, more particularly in the form of nanoparticles. Environmentally friendly synthesis methods are becoming more and more popular in chemistry and chemical technologies and the need for ecological methods of synthesis is increasing; the aim is to reduce polluting reaction by-products. Another important advantage of green synthesis methods lies in its cost-effectiveness and in the abundance of raw materials. During the last five years, many efforts were put into developing new greener and cheaper methods for the synthesis of nanoparticles. The cost decrease and less harmful synthesis methods have been the motivation in comparison to other synthesis techniques where harmful reductive organic species produce hazardous by-products. This environment-friendly aspect has now become a major social issue and is instrumental in combatting environmental pollution through reduction or elimination of hazardous materials. This review describes a brief overview of the research on green synthesis of silver metal nanoparticles and the influence of the method on their size and morphology.

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Creating the Wind

Latin American and Latinx Visual Culture ◽

10.1525/lavc.2020.2.4.14 ◽

2020 ◽

Vol 2 (4) ◽

pp. 14-31

Author(s):

Élodie Dupey García

Keyword(s):

Indigenous Communities ◽

The Body ◽

Historical Sources ◽

Natural Behavior ◽

Sensory Experiences ◽

Identity And Agency ◽

Wide Range ◽

Late Postclassic ◽

Comparative Examination ◽

Meteorological Phenomenon

This article explores how the Nahua of late Postclassic Mesoamerica (1200–1521 CE) created living and material embodiments of their wind god constructed on the basis of sensory experiences that shaped their conception of this divinized meteorological phenomenon. In this process, they employed chromatic and design devices, based on a wide range of natural elements, to add several layers of meaning to the human, painted, and sculpted supports dressed in the god’s insignia. Through a comparative examination of pre-Columbian visual production—especially codices and sculptures—historical sources mainly written in Nahuatl during the viceregal period, and ethnographic data on indigenous communities in modern Mexico, my analysis targets the body paint and shell jewelry of the anthropomorphic “images” of the wind god, along with the Feathered Serpent and the monkey-inspired embodiments of the deity. This study identifies the centrality of other human senses beyond sight in the conception of the wind god and the making of its earthly manifestations. Constructing these deity “images” was tantamount to creating the wind because they were intended to be visual replicas of the wind’s natural behavior. At the same time, they referred to the identity and agency of the wind god in myths and rituals.

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Direct manipulation of particle size and morphology of ordered mesoporous silica by flow synthesis

RSC Advances ◽

10.1039/c4ra16679e ◽

2015 ◽

Vol 5 (18) ◽

pp. 13331-13340 ◽

Cited By ~ 27

Author(s):

T. N. Ng ◽

X. Q. Chen ◽

K. L. Yeung

Keyword(s):

Particle Size ◽

Mesoporous Silica ◽

Hollow Spheres ◽

Ordered Mesoporous Silica ◽

Direct Manipulation ◽

Flow Synthesis ◽

Precise Control ◽

Ordered Mesoporous ◽

Particle Size And Morphology ◽

Size And Morphology

Flow-synthesis of mesoporous silica allows deliberate and precise control over the size and shapes and enables the preparation of complex microstructures (i.e., hollow spheres).

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Rapid hot-injection as a tool for control of magnetic nanoparticle size and morphology

RSC Advances ◽

10.1039/d1ra02977k ◽

2021 ◽

Vol 11 (34) ◽

pp. 20708-20719

Author(s):

Magdalena Kulpa-Greszta ◽

Anna Tomaszewska ◽

Andrzej Dziedzic ◽

Robert Pązik

Keyword(s):

Particle Shape ◽

Magnetic Nanoparticle ◽

Magnetic Particle ◽

Nanoparticle Size ◽

Precise Control ◽

Hot Injection ◽

Size And Morphology

Rapid hot-injection can be used for precise control of magnetic particle shape.

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Development and Validation of a New Scoring Tool to Evaluate the Clinical Evolution of Adult Patients with Nonsegmental Vitiligo

Dermatology ◽

10.1159/000511890 ◽

2021 ◽

pp. 1-9

Author(s):

María Luisa Peralta-Pedrero ◽

Denisse Herrera-Bringas ◽

Karla Samantha Torres-González ◽

Martha Alejandra Morales-Sánchez ◽

Fermín Jurado Santa-Cruz ◽

...

Keyword(s):

Body Surface ◽

Task Force ◽

Intraclass Correlation ◽

The Body ◽

Response To Treatment ◽

Similar Response ◽

Clinical Evolution ◽

Wide Range ◽

Patient Reported ◽

Extreme Groups

Background: Vitiligo has an unpredictable course and a variable response to treatment. Furthermore, the improvement of some vitiligo lesions cannot be considered a guarantee of a similar response to the other lesions. Instruments for patient-reported outcome measures (PROM) can be an alternative to measure complex constructions such as clinical evolution. Objective: The aim of this study was to validate a PROM that allows to measure the clinical evolution of patients with nonsegmental vitiligo in a simple but standardized way that serves to gather information for a better understanding of the disease. Methods: The instrument was created through expert consensus and patient participation. For the validation study, a prospective cohort design was performed. The body surface area affected was measured with the Vitiligo Extension Score (VES), the extension, the stage, and the spread by the evaluation of the Vitiligo European Task Force assessment (VETFa). Reliability was determined with test-retest, construct validity through hypothesis testing, discriminative capacity with extreme groups, and response capacity by comparing initial and final measurements. Results: Eighteen semi-structured interviews and 7 cognitive interviews were conducted, and 4 dermatologists were consulted. The instrument Clinical Evolution-Vitiligo (CV-6) was answered by 119 patients with a minimum of primary schooling. A wide range was observed in the affected body surface; incident and prevalent cases were included. The average time to answer the CV-6 was 3.08 ± 0.58 min. In the test-retest (n = 53), an intraclass correlation coefficient was obtained: 0.896 (95% CI 0.82–0.94; p < 0.001). In extreme groups, the mean score was 2 (2–3) and 5 (4–6); p < 0.001. The initial CV-6 score was different from the final one and the change was verified with VES and VETFa (p < 0.05, n = 92). Conclusions: The CV-6 instrument allows patient collaboration, it is simple and brief, and it makes it easier for the doctor to focus attention on injuries that present changes at the time of medical consultation.

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Hydromechanics of low-Reynolds-number flow. Part 2. Singularity method for Stokes flows

Journal of Fluid Mechanics ◽

10.1017/s0022112075000614 ◽

1975 ◽

Vol 67 (4) ◽

pp. 787-815 ◽

Cited By ~ 300

Author(s):

Allen T. Chwang ◽

T. Yao-Tsu Wu

Keyword(s):

Exact Solutions ◽

Stokes Flow ◽

Fundamental Solutions ◽

The Body ◽

Circular Cylinders ◽

Geometrical Parameters ◽

Flow Problems ◽

Singularity Method ◽

Wide Range ◽

Body Shapes

The present study further explores the fundamental singular solutions for Stokes flow that can be useful for constructing solutions over a wide range of free-stream profiles and body shapes. The primary singularity is the Stokeslet, which is associated with a singular point force embedded in a Stokes flow. From its derivatives other fundamental singularities can be obtained, including rotlets, stresslets, potential doublets and higher-order poles derived from them. For treating interior Stokes-flow problems new fundamental solutions are introduced; they include the Stokeson and its derivatives, called the roton and stresson.These fundamental singularities are employed here to construct exact solutions to a number of exterior and interior Stokes-flow problems for several specific body shapes translating and rotating in a viscous fluid which may itself be providing a primary flow. The different primary flows considered here include the uniform stream, shear flows, parabolic profiles and extensional flows (hyper-bolic profiles), while the body shapes cover prolate spheroids, spheres and circular cylinders. The salient features of these exact solutions (all obtained in closed form) regarding the types of singularities required for the construction of a solution in each specific case, their distribution densities and the range of validity of the solution, which may depend on the characteristic Reynolds numbers and governing geometrical parameters, are discussed.

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A Computational Study on the Role of Parameters for Identification of Thyroid Nodules by Infrared Images (and Comparison with Real Data)

Sensors ◽

10.3390/s21134459 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4459

Author(s):

José R. González ◽

Charbel Damião ◽

Maira Moran ◽

Cristina A. Pantaleão ◽

Rubens A. Cruz ◽

...

Keyword(s):

Heat Transfer ◽

Thyroid Nodules ◽

Numerical Study ◽

Computational Study ◽

Internal Heat ◽

Heat Transfer Process ◽

The Body ◽

Physical Parameters ◽

Infrared Sensors ◽

Wide Range

According to experts and medical literature, healthy thyroids and thyroids containing benign nodules tend to be less inflamed and less active than those with malignant nodules. It seems to be a consensus that malignant nodules have more blood veins and more blood circulation. This may be related to the maintenance of the nodule’s heat at a higher level compared with neighboring tissues. If the internal heat modifies the skin radiation, then it could be detected by infrared sensors. The goal of this work is the investigation of the factors that allow this detection, and the possible relation with any pattern referent to nodule malignancy. We aim to consider a wide range of factors, so a great number of numerical simulations of the heat transfer in the region under analysis, based on the Finite Element method, are performed to study the influence of each nodule and patient characteristics on the infrared sensor acquisition. To do so, the protocol for infrared thyroid examination used in our university’s hospital is simulated in the numerical study. This protocol presents two phases. In the first one, the body under observation is in steady state. In the second one, it is submitted to thermal stress (transient state). Both are simulated in order to verify if it is possible (by infrared sensors) to identify different behavior referent to malignant nodules. Moreover, when the simulation indicates possible important aspects, patients with and without similar characteristics are examined to confirm such influences. The results show that the tissues between skin and thyroid, as well as the nodule size, have an influence on superficial temperatures. Other thermal parameters of thyroid nodules show little influence on surface infrared emissions, for instance, those related to the vascularization of the nodule. All details of the physical parameters used in the simulations, characteristics of the real nodules and thermal examinations are publicly available, allowing these simulations to be compared with other types of heat transfer solutions and infrared examination protocols. Among the main contributions of this work, we highlight the simulation of the possible range of parameters, and definition of the simulation approach for mapping the used infrared protocol, promoting the investigation of a possible relation between the heat transfer process and the data obtained by infrared acquisitions.

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Amine-Grafted Mesoporous Carbons as Benzocaine-Delivery Platforms

Materials ◽

10.3390/ma14092188 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2188

Author(s):

Joanna Goscianska ◽

Aleksander Ejsmont ◽

Anita Kubiak ◽

Dominika Ludowicz ◽

Anna Stasiłowicz ◽

...

Keyword(s):

Release Kinetics ◽

The Body ◽

Therapeutic Drug ◽

Mesoporous Carbons ◽

Precise Control ◽

Pharmaceutical Ingredients ◽

Sorption Ability ◽

Porous Carriers ◽

Textural Parameters ◽

Amine Groups

Smart porous carriers with defined structure and physicochemical properties are required for releasing the therapeutic drug with precise control of delivery time and location in the body. Due to their non-toxicity, ordered structure, and chemical and thermal stability, mesoporous carbons can be considered modern carriers for active pharmaceutical ingredients whose effectiveness needs frequent dosing algorithms. Here, the novel benzocaine delivery systems based on ordered mesoporous carbons of the cubic structure were obtained with the use of a hard template method and functionalization with amine groups at 40 °C for 8 h. It has been shown that amine grafting strongly modifies the surface chemistry and textural parameters of carbons. All samples indicated good sorption ability towards benzocaine, with evident improvement following the functionalization with the amine groups. The sorption capacity and drug release kinetics were strongly affected by the porosity of carbon carriers and the surface functional groups. The smallest amount of benzocaine (~12%) was released from pristine mesoporous carbon, which could be correlated with strong API–carrier interactions. Faster and more efficient release of the drug was observed in the case of triethylenetetramine modified carbon (~62%). All benzocaine delivery platforms based on amine-grafted mesoporous carbons revealed high permeability through the artificial membrane.

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