Artificial Substitutes Research Articles

Selective Detection of an Infection Biomarker by an Osteo-Friend Scaffold: Development of a Multifunctional Artificial Bone Substitute.

Developments in three-dimensional (3D) printing technologies have led to many potential applications in various biomedical fields, especially artificial bone substitutes (ABSs). However, due to the characteristics of artificial materials, biocompatibility and infection remain issues. Here, multifunctional ABSs have been designed to overcome these issues by the inclusion of a biochemical modality that allows simultaneous detection of an infection biomarker by osteo-friend 3D scaffolds. The developed multifunctional scaffolds consist of calcium-deficient hydroxyapatite (CDHA), which has a similar geometric structure and chemical composition to human bone, and gold nanoparticles (Au NPs), which assists osteogenesis and modulates the fluorescence of labels in their microenvironment. The Au NPs were subsequently conjugated with fluorescent dye-labeled probe DNA, which allowed selective interaction with a specific target biomarker, and the fluorescent signal of the dye was temporally quenched by the Au NP-derived Förster resonance energy transfer (FRET). When the probe DNA unfolded to bind to the target biomarker, the fluorescence signal was recovered due to the increased distance between the dye and Au NPs. To demonstrate this sensing mechanism, a microbial oligonucleotide was selected as a target biomarker. Consequently, the multifunctional scaffold simultaneously facilitated osteogenic proliferation and the detection of the infection biomarker.

Robust Electrospun Nanofibers from Chemosynthetic Poly(4-hydroxybutyrate) as Artificial Dural Substitute.

Bioresorbable poly(4-hydroxybutyrate) (P4HB) may fulfill the specific requirements that are necessary for a dural substitute, including its high elasticity, long-term strength retention properties, and the biocompatibility without significant accumulation of acidic degradation products. However, commercial P4HB can only be produced by the bacterial fermentation, which limits its applications in the cerebrospinal system due to higher endotoxin restriction. Meanwhile, P4HB can be prepared via the ring-opening polymerization of γ-butyrolactone. In this contribution, high molecular weight P4HB from chemosynthesis is electrospun into fibrous membrane, showing good mechanical properties that match the natural dura mater. Such P4HB membrane induces fast cellular migration, adhesion, and proliferation of fibroblasts in vitro. Subcutaneous implantation in rats demonstrates excellent biocompatibility of the P4HB membrane with proper biodegradation behaviors. After implantation in the rabbit dural defect model as an onlay graft, the P4HB membranes prevent cerebrospinal fluid leakage and regenerate dura tissue without detecting any local or systematic infections or foreign body responses. Thus, the electrospun P4HB membranes may be particularly useful as artificial dural substitutes to induce wound closure and tissue regeneration, which will be of great benefit to neurosurgery in the future.

Self-Powered Flexible Sour Sensor for Detecting Ascorbic Acid Concentration Based on Triboelectrification/Enzymatic-Reaction Coupling Effect.

Artificial sensory substitution systems can mimic human sensory organs through replacing the sensing process of a defective sensory receptor and transmitting the sensing signal into the nervous system. Here, we report a self-powered flexible gustation sour sensor for detecting ascorbic acid concentration. The material system comprises of Na2C2O4-Ppy with AAO modification, PDMS and Cu wire mesh. The working mechanism is contributed to the triboelectrification/enzymatic-reaction coupling effect, and the device can collect weak energy from body movements and directly output triboelectric current without any external power-units. The triboelectric output is affected by AA concentration, and the response is up to 34.82% against 15.625 mM/L of AA solution. Furthermore, a practical application in detecting ascorbic acid concentration of different drinks has been demonstrated. This work can encourage the development of wearable flexible electronics and this self-powered sour sensor has the potential that can be acted as a kind of gustatory receptors to build electronic tongues.

A comparative study on microemulsion synthesis of hydroxyapatite powders by ionic and Non-Ionic surfactants

Hydroxyapatite (HAP) [Ca10(PO4)6(OH)2] is an excellent bio-ceramic material for artificial bone substitution in biomedical field owing to its chemical and crystallographic similarities of natural bone and teeth. In this research work, we have attempted the synthesis of hydroxyapatite powders with controllable size in the presence of three different surfactants sodium dodecyl sulphate (SDS) which is an anionic surfactant, cetyl trimethylammonium bromide (CTAB) as a cationic surfactant and poly vinyl alcohol (PVA) as a non-ionic surfactant. The as-synthesised HAP powders were characterised by analytical techniques such as FTIR, XRD and SEM. The results have shown that the non-ionic surfactant is a better choice for developing this bio-nanomaterial due to its good dispersing power than CTAB and SDS. The results have also indicated that, nano-hydroxyapatite particle has a uniform morphology, well crystallinity and the particle size was controlled with the use of non-ionic surfactant. The crystallite size was calculated using Scherer’s formula. Experiments were performed under controlled environment by maintaining the required pH, concentration and temperature. The biomedical application studies of the as-synthesised material are yet to be studied.

Bioengineered Skin Intended as In Vitro Model for Pharmacosmetics, Skin Disease Study and Environmental Skin Impact Analysis.

This review aims to be an update of Bioengineered Artificial Skin Substitutes (BASS) applications. At the first moment, they were created as an attempt to replace native skin grafts transplantation. Nowadays, these in vitro models have been increasing and widening their application areas, becoming important tools for research. This study is focus on the ability to design in vitro BASS which have been demonstrated to be appropriate to develop new products in the cosmetic and pharmacology industry. Allowing to go deeper into the skin disease research, and to analyze the effects provoked by environmental stressful agents. The importance of BASS to replace animal experimentation is also highlighted. Furthermore, the BASS validation parameters approved by the OECD (Organisation for Economic Co-operation and Development) are also analyzed. This report presents an overview of the skin models applicable to skin research along with their design methods. Finally, the potential and limitations of the currently available BASS to supply the demands for disease modeling and pharmaceutical screening are discussed.

Resuscitation After Hemorrhagic Shock in the Microcirculation: Targeting Optimal Oxygen Delivery in the Design of Artificial Blood Substitutes.

Microcirculatory preservation is essential for patient recovery from hemorrhagic shock. In hemorrhagic shock, microcirculatory flow and pressure are greatly reduced, creating an oxygen debt that may eventually become irreversible. During shock, tissues become hypoxic, cellular respiration turns to anaerobic metabolism, and the microcirculation rapidly begins to fail. This condition requires immediate fluid resuscitation to promote tissue reperfusion. The choice of fluid for resuscitation is whole blood; however, this may not be readily available and, on a larger scale, may be globally insufficient. Thus, extensive research on viable alternatives to blood has been undertaken in an effort to develop a clinically deployable blood substitute. This has not, as of yet, achieved fruition, in part due to an incomplete understanding of the complexities of the function of blood in the microcirculation. Hemodynamic resuscitation is acknowledged to be contingent on a number of factors other than volume expansion. The circulation of whole blood is carefully regulated to optimize oxygen delivery to the tissues via shear stress modulation through blood viscosity, inherent oxygen-carrying capacity, cell-free layer variation, and myogenic response, among other variables. Although plasma expanders can address a number of these issues, hemoglobin-based oxygen carriers (HBOCs) introduce a method of replenishing the intrinsic oxygen-carrying capacity of blood. There continue to be a number of issues related to HBOCs, but recent advances in the next-generation HBOCs show promise in the preservation of microcirculatory function and limiting toxicities. The development of HBOCs is now focused on viscosity and the degree of microvascular shear stress achieved in order to optimize vasoactive and oxygen delivery responses by leveraging the restoration and maintenance of physiological responses to blood flow in the microcirculation. Blood substitutes with higher viscous properties tend to improve oxygen delivery compared to those with lower viscosities. This review details current concepts in blood substitutes, particularly as they relate to trauma/hemorrhagic shock, with a specific focus on their complex interactions in the microcirculation.

Cellular Response to Vitamin C-Enriched Chitosan/Agarose Film with Potential Application as Artificial Skin Substitute for Chronic Wound Treatment.

The treatment of chronic wounds is still a meaningful challenge to physicians. The aim of this work was to produce vitamin C-enriched chitosan/agarose (CHN/A) film that could serve as potential artificial skin substitute for chronic wound treatment. The biomaterial was fabricated by a newly developed and simplified method via mixing acidic chitosan solution with alkaline agarose solution that allowed to obtain slightly acidic pH (5.97) of the resultant material, which is known to support skin regeneration. Vitamin C was immobilized within the matrix of the film by entrapment method during production process. Produced films (CHN/A and CHN/A + vit C) were subjected to comprehensive evaluation of cellular response with the use of human skin fibroblasts, epidermal keratinocytes, and macrophages. It was demonstrated that novel biomaterials support adhesion and growth of human skin fibroblasts and keratinocytes, have ability to slightly reduce transforming growth factor-beta 1 (TGF-β1) (known to be present at augmented levels in the epidermis of chronic wounds), and increase platelet-derived growth factor-BB (PDGF-BB) secretion by the cells. Nevertheless, addition of vitamin C to the biomaterial formulation does not significantly improve its biological properties due to burst vitamin release profile. Obtained results clearly demonstrated that produced CHN/A film has great potential to be used as cellular dermal, epidermal, or dermo-epidermal graft pre-seeded with human skin cells for chronic wound treatment.

Development of Artificial Substitutes for Upper Digestive Tract: Personal Experience of Trials and Errors

The current treatments for esophageal diseases, such as carcinomas, trauma or congenital malformations, require surgical intervention, and esophageal reconstruction using redundant parts of the gastrointestinal tract. However, the use of gastrointestinal segments can cause various surgical morbidities and mortality because additional abdominal surgery may be required at the expense of other anatomic structures. Therefore, tissue engineering using various biomaterial or cell sources has emerged as an alternative strategy of biomimicking the native esophageal tissue that could be implanted as an artificial graft. Although tissue engineering techniques have promise as an effective regenerative strategy, no functional solution currently exists for esophageal reconstruction. Here, we present a review of the progress made in the field of regenerative medicine for esophageal reconstruction based on the personal experience. Key words: Epithelial cell ㆍ Esophagus ㆍ Smooth muscle cell ㆍ Tissue engineering ㆍ Tissue scaffolds

Editorial Preface on the Proceeding of International Conference on Design and Application of Engineering Materials (IC-DAEM).

International Conference on Design and Application of Engineering Materials 2018 (IC-DAEM) was the first international conference initiated by Materials Science and Engineering Research Group, Faculty of Mechanical and Aerospace Engineering, Institut Teknologi Bandung, Indonesia. The conference was held in Bandung Indonesia on 6th – 7th September 2018 in conjunction with annual national meeting entitled Seminar Nasional Metalurgi dan Material XI 2018 (SENAMM XI). The theme of the conference was “Emerging the knowledge of materials design to achieve better materials integrity” and was held as an honour for the retirement of Prof. Mardjono Siswosuwarno, which is considered as one of the pioneers in the field of failure analysis in Indonesia.The topics of interest of IC-DAEM 2018 included but were not limited to: materials design, development of synthesis and characterization method, experimental and computational work related to this topic, application aspect of engineering materials including materials degradation and failure analysis. Four keynote lectures were delivered on the topics of Production of Rare Earth Ortho-Ferrites from end-of-life Nd Magnets, Characterization of Calcium Phosphate Ceramics Synthesized by Heterogeneous Nucleation for Artificial Bone Substitutes, Development of Steel Matrix Composites Used for Metallic Die, and Effective Steps in Performing Failure Analysis.Papers presented in IC-DAEM 2018 are included in this proceeding after going through peer reviewing process. This proceeding contains papers with broad topics on design and application of engineering materials, such as (1) Inspection, Maintenance, Techniques and Managements, (2) Method and Case of Engineering Failure Analysis, (3) Time Dependent Properties and Degradation of Engineering Materials, (4) Computational Modelling and Simulation, (5) Development of Synthesis and Characterization Methods, (6) Laboratory and Full Scale-Scale Experiments, (7) Materials and Alloy Design, and (8) Materials Property Improvement. We hope that these papers will immensely benefit the research community working in Materials Science and Engineering, both in the academic and industrial fields.

Enhancement of the Electrical Properties of DNA Molecular Wires through Incorporation of Perylenediimide DNA Base Surrogates.

DNA has long been viewed as a promising material for nanoscale electronics, in part due to its well-ordered arrangement of stacked, pi-conjugated base pairs. Within this context, a number of studies have investigated how structural changes, backbone modifications, or artificial base substitutions affect the conductivity of DNA. Herein, we present a comparative study of the electrical properties of both well-matched and perylene-3,4,9,10-tetracarboxylic diimide (PTCDI)-containing DNA molecular wires that bridge nanoscale gold electrodes. By performing current-voltage measurements for such devices, we find that the incorporation of PTCDI DNA base surrogates within our macromolecular constructs leads to an approximately 6-fold enhancement in the observed current levels. Together, these findings suggest that PTCDI DNA base surrogates may enable the preparation of designer DNA-based nanoscale electronic components.

Effect of Botulinum toxin Aapplication in neuro-ophtalmologic indications on Schirmerstest and tears osmolarity.

Botulinum toxin type A(BT-A) is used in the treatment of neuro-ophthalmologic disorders such as essential blepharospasm and facial hemispasm for more than 20 years. Although the long-term effect of repeated application of the BT-Awas confirmed, the BT-Aeffect on tears production and retention is not clear. In our work we investigated whether applied BT-Ain patients with blepharospasm and hemifacial spasm affect tears production. Tears quality was measured with Schirmersand tear osmolarity test during neuro-ophthalmologic diseases treatment, which was evaluated before and 14 days after application of BT-A(Botox inj, Allergan, Irvine, USA) into the orbicularis oculi muscle. BT-Adoses of 16-18 Uwith unilateral and 32 to 36 Ubilateral applications were used. The mean tear production in Schirmerstest before BT-Aapplication was 8.38 ± 0.63 mm, and 2 weeks after BT-Aapplication was 7.12 ± 0,6 mm (n = 50). Tear osmolarity was 305.4 ± 9.2 mOsm before BT-Aapplication, and 2 weeks after BT-Aapplication it was 305.2 ± 8,6 mOsm (n = 13). We found significant difference between two groups in tear quantity (p < 0.012), but not quality (p > 0.05). Application of the BT-Areduced the amount of tears measured by Schirmerstest. These results confirm rational basis of the empirical clinical experience where an artificial tears substitution is recommended for patients with neuro-ophthalmologic disorders treated by BT-A.

Evolution of the concept of quality of life in the population in end stage renal disease. A systematic review of the literature.

Given the rising prevalence of end-stage renal disease and subsequent progressive increase of patients starting renal replacement therapy, a great attention is given by scientific community to the assessment of life perception and Quality of Life (QoL) in dialysis patients. A broad literature review was conducted on PubMed and PsyInfo databases for articles published between January 2000 and July 2016 in order to understand the biological and psychosocial variables potentially affecting the QoL of the patients under artificial substitution of kidney function. Five domains related to the concepts of physical functions, mood, sleep, spirituality, and social support have been identified. The findings in this review suggest that the variables related to physical activity and depression seem to have a direct impact on QoL and Health-Related Quality of Life (HRQoL). Others, such as anxiety, awareness, empowerment, the presence of sleep disorders, satisfaction, support from the staff, social support, spirituality and religion have a clear correlation with the QoL dimensions. These results suggest the primary importance of the assessment biological and psychosocial variables by specific tools and the inclusion of effective interventions targeted to patients and their caregivers.

Штучний інтелект у процесі праці у цифровій економіці: нові виклики та можливості

Active introduction of digital technologies in all spheres of human life transforms business models, accelerates the process of entry of enterprises into the global market, creates new conditions for hiring personnel, replaces certain types of human labor with algorithms and machines. At the same time, digitization and technological innovation open up opportunities: new jobs, expanding employment, revealing a person's creative potential. This requires new approaches to understanding the processes of transformation of the labor process in the digital economy, identifying the benefits of employee over the machine in the labor field, and developing measures to strengthen the position of the employee in the digital labor market. The article studies the issues of transforming the place and role of artificial intelligence and employee in the labor process in the digital economy. Attention is focused on reducing the share of human labor and reducing demand in some types of activity while increasing its value in other areas. Classification of human labor is proposed, which is based on an assessment of the possibility of replacing an employee with artificial intelligence. The place and role of artificial intelligence and employee in routine, creative, social activities are determined. At the risk of reducing demand for labor until it is completely replaced by technology are jobs that involve routine operations, and vice versa, the value of human labor increases in creative activities. A two-factor model has been developed that classifies labor activity according to a combination of complexity and creativity. On the basis of the proposed matrix, the types of activities subject to artificial intelligence substitution are detailed. Possible trends in the transformation of artificial intelligence from an object of the labor market into a subject are identified: partially or completely, subject to legislative regulation of the legal status of artificial intelligence. It is determined that social labor cannot be replaced by artificial intelligence. The advantages and disadvantages of the following activities were identified: routine, creative, social. It is determined that the main directions of strengthening the position of the employee in the labor market are the formation of a favorable environment for the development of creative potential of the person and the realization of the concept of lifelong learning. These areas require support from national and regional authorities and their engagement with interested and proactive local communities.

73 Artificial incubation of resplendent quetzal (Pharomachrus mocinno mocinno) eggs

The scientific literature lacks information regarding the incubation conditions and hatching success of the resplendent quetzal (Pharomachrus mocinno mocinno). Jesús Estudillo López, founder of the El Nido aviary, was the first to succeed with quetzal reproduction in captivity. Quetzals do not typically reproduce in captivity and the aim of this study was to increase fecundity through artificial incubation. Over a 3-year period (Yr1, Yr2, and Yr3), data about quetzal eggs, artificial incubation, and diet were recorded for 3 quetzal pairs (ranging from ~4-12 years old, with females ~4-8 years old). Eggs were manually collected from artificial nests and egg substitution was utilised. Quetzals can continue laying eggs up to 8 times with egg substitution. Eggs were weighed and placed into an 80W incubator (INCA 200®, DMP Engineering, Tel Aviv, Israel) with an automatic egg turner. The eggs were incubated for 17 to 18 days at 37.2 to 37.6°C with a relative humidity of 20 to 40%. Fisher’s exact test (2-tailed, α=0.05) was used for statistical analyses comparing the numbers of eggs hatched, infertile eggs, and eggs experiencing embryonic death for the study period. Eggs were candled on Day 3 to determine fertility by the presence of a darker area with vasculogenesis. Hatchability (%) was determined by dividing the total number of offspring hatched by the total number of eggs deemed fertile after candling. All of the eggs that did not hatch were opened at the end of the incubation period to detect early embryo death. A total of 27 quetzal eggs [mean weight (g)=17.3, s.d.=1.2] were incubated over 3 years, of which 10 (~37%) hatched, with 3 (30%) fledging and surviving to adulthood. Six of the eggs (~22%) suffered embryonic mortality during incubation, whereas 11 eggs were infertile (~41%). Hatchability over the study period was 62.5% (10/16). During Yr1 and Yr2 two eggs hatched each year, and compared with the 6 eggs that hatched in Yr3, a noteworthy but not significant difference was observed (Yr1v. Yr2, P=1; Yr1v. Yr3, P=0.188; Yr2v. Yr3, P=0.170). Embryonic death of the eggs was also not significantly different between the years (Yr1v. Yr2, P=1; Yr1v. Yr3, P=0.314; Yr2v. Yr3, P=0.303). However, the number of infertile eggs was significantly different between Yr1v. Yr3 (P=0.007) and Yr2v. Yr3 (P=0.003), but not Yr1v. Yr2 (P=1). During Yr1 and Yr2 the diet consisted of fruit (aguacatillo, banana, and papaya) and a mouse pup once a week. In Yr3 the diet was modified to include blueberry and a commercial food for Tucans (Mazuri®; https://www.mazuri.com/) and a new quetzal pair was added. The modified diet will continue to be used given that there were fewer infertile eggs. However, future research will need to be conducted to elucidate which variables specifically contribute to better hatching results. The results of this study demonstrate an assisted reproductive technique for quetzals that can benefit conservation efforts for this species.

Soluble Prefusion Closed DS-SOSIP.664-Env Trimers of Diverse HIV-1 Strains

The elicitation of autologous neutralizing responses by immunization with HIV-1 envelope (Env) trimers conformationally stabilized in a prefusion closed state has generated considerable interest in the HIV-1 vaccine field. However, soluble prefusion closed Env trimers have been produced from only a handful of HIV-1 strains, limiting their utility as vaccine antigens and B cell probes. Here, we report the engineering from 81 HIV-1 strains of soluble, fully cleaved, prefusion Env trimers with appropriate antigenicity. We used a 96-well expression-screening format to assess the ability of artificial disulfides and Ile559Pro substitution (DS-SOSIP) to produce soluble cleaved-Env trimers; from 180 Env strains, 20 yielded prefusion closed trimers. We also created chimeras, by utilizing structure-based design to incorporate select regions from the well-behaved BG505 strain; from 180 Env strains, 78 DS-SOSIP-stabilized chimeras, including 61 additional strains, yielded prefusion closed trimers. Structure-based design thus enables the production of prefusion closed HIV-1-Env trimers from dozens of diverse strains.

Experimental and Theoretical Study on Isotopic Surface-Enhanced Raman Spectroscopy for the Surface Catalytic Coupling Reaction on Silver Electrodes

Surface-enhanced Raman Spectroscopy (SERS) as a unique spectroscopic tool has been broadly used to detect surface reactions, yet normal SERS detection and theoretical simulation cannot satisfy the urgent need of revealing detailed reaction mechanisms. Here, we introduce an isotopic SERS method to demonstrate the occurrence of surface chemical reactions theoretically and experimentally. Isotopic effects on Raman vibrational frequency and intensity due to the change of reduced masses and the vibrational coupling were verified by DFT simulations and its corresponding isotopic SERS measurements. Taking surface catalytic coupling reactions of PATP/PNTP to DMAB on silver surfaces as the modeling system, we first created chemically identical yet vibrationally distinct isotopologues of redox species by artificial isotopic substitution. Our theoretical and experimental results both showed the isotopic effects have obviously different features in the fundamental frequencies and the relative intensities in the Raman...

The Role of Resorbable Plate and Artificial Bone Substitute in Reconstruction of Large Orbital Floor Defect.

It is essential to reduce and reconstruct bony defects adequately in large orbital floor fracture and defect. Among many reconstructive methods, alloplastic materials have attracted attention because of their safety and ease of use. We have used resorbable plates combined with artificial bone substitutes in large orbital floor defect reconstructions and have evaluated their long-term reliability compared with porous polyethylene plate. A total of 147 patients with traumatic orbital floor fracture were included in the study. Surgical results were evaluated by clinical evaluations, exophthalmometry, and computed tomography at least 12 months postoperatively. Both orbital floor height discrepancy and orbital volume change were calculated and compared with preoperative CT findings. The average volume discrepancy and vertical height discrepancies were not different between two groups. Also, exophthalmometric measurements were not significantly different between the two groups. No significant postoperative complication including permanent diplopia, proptosis, and enophthalmos was noted. Use of a resorbable plate with an artificial bone substitute to repair orbital floor defects larger than 2.5 cm2 in size yielded long-lasting, effective reconstruction without significant complications. We therefore propose our approach as an effective alternative method for large orbital floor reconstructions.

Computerized 3D Modeling for Rapid Artificial Bone Substitute Manufacturing

bone substitutes manufacturing is highly important due to a vast number casualties are stepped to the society as a result of mainly traffic accidents, natural disasters and civil wars. Though casualties are grouped into several categories, a considerable number of patients is fallen into the bone associated injuries. It is also notable that especially the traffic related accidents and natural disasters may occur in populated regions. Due to financial reasons all the hospitals in the developing countries cannot maintain sophisticated scanning equipments along with their software solutions. Therefore having a lightweight software solution that facilitates bone profiling will be beneficial for patients and it also helps surgeons to prepare a care plan depending on the disorder. However, the artificial tools that are inserted to the human body can vary upon the injury. Hence, they should be highly customizable. Though computerized 3D modeling started around two decades ago, a few tools are available to assist surgeons in such situations. The available applications and techniques have limited functionalities thus, the manufactured bone grafts may not perfectly be suited to the lesion or injury. In this paper we propose a minimally invasive procedures to model bone grafts. In which, quality control methods for noise removals and 3D data compression mechanisms are coupled to the software solution that runs even on typical personal computer systems. The end result of the 3D modeled bone can be employed to extract the cavity, clip regions of interest and even to test the manufactured bone graft before the surgical procedure. Thereby, the process of manufacturing the prosthetic and the clinical procedures will be efficient and reliable.

The Utility of an Artificial Substitute to Improve Corneal Sensitivity in Glaucomatous Patients on Chronic Therapy with Prostaglandin Analogs

To evaluate whether a tear substitute can improve corneal subepithelial nerve plexus and corneal sensitivity in glaucomatous patients. This study was prospective, longitudinal, and single arm. Twenty glaucomatous patients were recruited. All the patients were treated with a prostaglandin analog with preservative for at least 1 year. Preservative-free artificial tears (0.5% tamarind seed polysaccharide 0.5(®) eye drops single-dose preservative free [Oftagen]) were prescribed thrice per day. The participants were subjected to clinical and instrumental evaluation at baseline (T0), after 1 month (T1) and after 3 months (T3) of treatment. All patients were examined with a digital corneal confocal laser-scanning microscope (HRT II Rostock Cornea Module; Heidelberg Engineering GmbH) and Cochet-Bonnet corneal esthesiometer. After the artificial substitute, corneal and conjunctival sensitivity significantly (P < 0.001) improved at T1 and T3 compared to the baseline. A significant correlation was found between break-up time and both central corneal sensitivity and the number of fibers. The use of a preservative-free artificial substitute in association with a topical therapy with chronic preservative could increase the compliance of patients.

Dissolution Behavior of Various Artificial Bone Substitutes in the Acid Environment Mimicking the Subosteoclastic Zone

Dissolution Behavior of Various Artificial Bone Substitutes in the Acid Environment Mimicking the Subosteoclastic Zone