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This article presents a comprehensive review of the topic of placebos, with a special focus on placebo analgesia. It includes a discussion of how placebos work (the placebo effect) and how patients react to them (the placebo response). A literature search was performed to identify relevant literature and publications related to the topic, and a qualitative assessment of papers was undertaken based on accepted rules for scientific evidence. The major finding from this review was that concepts about placebo effects and responses have changed dramatically over the years, especially in more recent years. This has occurred primarily as a result of more sophisticated experimental protocols using placebos in clinical studies of patients in pain, as well as various studies involving normal subjects. Our understanding of the biological and psychological mechanisms underlying placebo effects has expanded significantly due to recent developments in the technology of brain imaging. Based on findings from brain-imaging analyses, we now know that placebo analgesia is definitely a real (ie, biologically measurable) phenomenon. It can be pharmacologically blocked and behaviorally enhanced, and these responses have been demonstrated to be similar to those elicited by administration of "real" analgesic substances. Psychological mechanisms involved in placebo analgesia include expectancy, meaning response, and classical conditioning. This article concludes with an emphasis on understanding therapeutic responses to various treatments for temporomandibular disorders (TMD). Acupuncture and splint therapy can be good examples of powerful placebos in the field of TMD, and both of these are discussed in detail. Present knowledge suggests that every treatment for pain contains a placebo component, which sometimes is as powerful as the so-called "active" counterpart. While the deceptive use of placebos must be considered unethical, every health provider who is treating pain patients must be aware of this important phenomenon in order to harness its huge potential. [ABSTRACT FROM AUTHOR]

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The research in the field of biomaterials has largely focused on the development of methods to enhance their bioactivity. Adopted strategies include chemical-physical approaches, but mainly the use of monoclonal antibodies, which confer the system target specificity. However, antibodies are marred by numerous issues, such as low physical-chemical stability or the risk of inducing immunological responses in the host, which often make their use difficult. Aptamers - a new class of molecules discovered in the early nineties - are small oligonucleotides, or in some cases peptides, and have been proposed to rival antibodies in biomedicine, countering at least some of the antibody-related drawbacks. The aim of this review is to provide a background to nucleic acid aptamers and to explore their novel applications. In addition to providing brief overview of their therapeutics applications, here we have assessed the methods that employ aptamers to improve the bioactivity of biomaterials, in particular, those that enhance targeting properties of drug delivery systems for chemotherapy, and those ameliorating scaffold biocompatibility for tissue engineering approaches. [ABSTRACT FROM AUTHOR]

The host-material interface is a crucial relationship dictating the possibility of successful osseointegration in implant dentistry. The aim of the present study was to characterize the effects of plasma proteins pre-adsorption on the adhesion capacity of osteoblasts, which occurs immediately after implant insertion in vivo. After having pre-adsorbed human plasma proteins on a machined and microrough titanium surface, MC3T3-E1 osteoblasts adhesion was evaluated through crystal violet cell adhesion assay, immunofluorescence staining for cytoskeleton, focal adhesions and cell nuclei, and scanning electron microscopy. The pre-adsorbed protein layer markedly affected the adhesion rate of cells, as well as their morphology and the expression of focal contacts. Moreover, protein adsorption to the underlying titanium surface was found to be correlated to surface pre-wetting. Thus, the early adsorption of serum proteins to the interface of dental implants impacts cell adhesion in terms of strength and of focal adhesions expression. [ABSTRACT FROM AUTHOR]

Tissue engineering (TE) is a multidisciplinary science, which including principles from material science, biology and medicine aims to develop biological substitutes to restore damaged tissues and organs. A major challenge in TE is the choice of suitable biomaterial to fabricate a scaffold that mimics native extracellular matrix guiding resident stem cells to regenerate the functional tissue. Ideally, the biomaterial should be tailored in order that the final scaffold would be (i) biodegradable to be gradually replaced by regenerating new tissue, (ii) mechanically similar to the tissue to regenerate, (iii) porous to allow cell growth as nutrient, oxygen and waste transport and (iv) bioactive to promote cell adhesion and differentiation. With this perspective, this review discusses the options and challenges facing biomaterial selection when a scaffold has to be designed. We highlight the possibilities in the final mold the materials should assume and the most effective techniques for its fabrication depending on the target tissue, including the alternatives to ameliorate its bioactivity. Furthermore, particular attention has been given to the influence that all these aspects have on resident cells considering the frontiers of materiobiology. In addition, a focus on chitosan as a versatile biomaterial for TE scaffold fabrication has been done, highlighting its latest advances in the literature on bone, skin, cartilage and cornea TE. [ABSTRACT FROM AUTHOR]