The soft-tissue response to implants of chitosan foils

The objective of our in vivo study was to investigate the biocompatibility of polymer foils enriched with chitosan. Methods: three types of chitosan: non-modified(jp), and modified with montmorillonite K5 and montmorillonite K10 (p2-p3) were prepared. The in vivo studies were carried out using the rat soft tissues as a model. Small pieces of foils (2mm x 4mm)used in the experiment were sterilized by UV radiation. Next they were implanted under sterile conditions into the gluteus muscle of adult male outbred Wistar rats. Each animal received two implants: the modified foil into the right muscle, and the unmodifiedfoil used as a control into the left one. All procedures were conducted in sterile conditions and under anaesthesia. Animals were anesthetized with intraperitoneal injection of xylazine and ketamine (Biowet Puławy, Poland). Skin in the site of surgery was shaved and disinfected, and a small incision was made in the gluteus muscle. Equal pieces of foils were inserted into the such created pouch. The muscle and skin wounds were closed with 5/0 PDSII (polydioxanone) monofilament absorbable sutures (Ethicon Ltd., UK). All animals survived the surgery. No wound healing complications were observed after the surgery. The animals were maintained under standard conditions with free access to food and water. After 7, and 30 days from the surgery, at each time point 12animals were sacrificed. Tissue specimens containing the implanted materials were excised and immediately frozen in liquid nitrogen. Next they were cut into 8μm thick slides in a Shandon cryostat (Thermo-Scientific, UK) at -22°C. Obtained slides were investigated through histological and histochemical methods to estimate the intensity of inflammation, production of collagen, and metabolic activity of connective and muscle tissues surrounding implant. In order to estimate the effect of the implants on the metabolic state of surrounding tissues, activities of the marker metabolic enzymes: cytochrome c oxidase, and NADH dehydrogenase were examined. The activity of acid phosphatase was used to assess the extent of inflammation around the implants. The presence and thickness of fibrous capsule around the implants were estimated on slides stained by van Gieson’s method. Results: Differences between non-modified and modified with chitosan materials were not manifested in short, 7- and 30 days series. The activities of mitochondrial oxidative enzymes, cytochrome c oxidase and NADH dehydrogenase, in muscle fibres in close proximity to the implants were slightly lower than in those further away. Probably one month was too short period to obtain the whole recovery after the surgery. At the same time the process of regeneration seemed to be intense: numerous regenerating muscle fibres infiltrated the granulation tissue around the implanted foils were observed The inflammation respone was visibly lower in 30days series compared to7days ones what indicate that the inflammation was evoked in higher degree by surgery than by the presence of the implanted materials. The fibrous capsule around foils was thin or not present at all – there were places where pieces of foils were in direct contact with the muscle tissue. After one month experiment there were no signs of degradation of materials. The experiment has been continued to compare abilities of biomaterials in long term series. Conclusion: The regeneration and enzymic activity of muscle tissue together with the lack of continuous fibrous capsule suggest that the materials used in our study are biocompatibile and are suitable for the treatment of tissue injury

Soft tissue response to degradation products of carbon biomaterials : a histochemical study

The regeneration processes of soft tissues in the presence of carbon biomaterials implants of three types were investigated using histochemical methods. Biomaterials in the form of powder, implanted into the rat muscle did not cause a disadvantage of celIs functions expressed by the activity of main enzymes of metabolic pathway and by the tissue regeneration processes

Porous carbon fibres for medical applications

Praca prezentuje wyniki badań nad otrzymywaniem włókniny węglowej, zbudowane/ z porowatych włókien. W literaturze opisywane są liczne próby stosowan/a włókien węglowych w medycynie. Przedmiotem badań byty włókna węglowe, różniące się stopniem krystaliczności, ilością heteroatomów, właściwościami mechanicznymi, jednakże wszystkie z tych włókien były materiałami nieporowatymi. Włókna węglowe, pomimo biozgodności, nie posiadają, w zadawalającym stopniu cech, które stymulowałyby regeneracje tkanki chrzęstnej. Z doniesień literaturowych wynika, że proces odbudowy chrząstki w obecności implantu węglowego trwa wiele miesięcy [1, 2]. Porowata włóknina węglowa stosowana jako implant do regeneracji tkanek mogłaby jednocześnie być nośnikiem różnego rodzaju leków lub aktywnych biologiczne cząstek przyspieszających odbudowę tkanki. W pracy przedstawiono analizę mikrostruktury włókien węglowych oraz wyniki badań biozgodności w warunkach in vivo. Wykazano, że biozgodność włókien porowatych jest lepsza w porównaniu z włóknami nieporowatymi.The work describes the preparation of carbon fabrics composed of porous fibres. In the literature a number of studies devoted to the applications of carbon fibres in medicine can be found. They deal with fibres which differ in the degree of crystallinity, the numer of heteroatoms, mechanical properties but all of them have been the nonporous materials. In spite of their biocompatibility, carbon fibres do not exhibit satisfactory features which would stimulate the regeneration of cartilage tissue. From literature data it follows that in the presence of a carbon implant tissue growth is a long-lasting process [1,2}. Porous carbon fabrics used as an implant for tissues regeneration could simultaneously seve as a support for delivery of drugs or biologically active agents which would stimulate the tissue growth. In the work the microstructure of carbon fibres as we/I as the results of in vivo biocompatibility studies are presented. It is shown that biocompatibilty of porous fibres is higher than that of nonporous ones

Current state of knowledge on the use of cannabidiol (CBD) in various medical conditions

INTRODUCTION AND PURPOSECannabis sativa contains hundreds of compounds, referred to as cannabinoids. Two most prevalent are delta-9-tetrahydrocannabinol and cannabidiol (CBD). CBD is non-psychoactive substance that has recently gained attention in lay press and in medical research. Aim of this study is to review evidence-based data on safety, effectiveness and applicability of CBD in various medical conditions in order to provide healthcare professionals with information that may be useful in their practice.MATERIALS AND METHODSIn April 2023, PubMed and Google Scholar databases were searched for studies that included phrases “CBD” or “cannabidiol”, and related phrases. In the review, only studies that used well-established research methods were included.RESULTSCBD is an effective novel treatment option in Lennox–Gastaut syndrome, tuberous sclerosis complex and Dravet syndrome. Data supporting CBD’s applicability in anxiety, Parkinson’s Disease, schizophrenia, insomnia, pain, autoimmune diseases, osteoporosis and as an anti-aging agent is promising, but more research on bigger groups of patients is needed to establish its role in modern medicine.CONCLUSIONSThe use of CBD is associated with risks of variable dosage, contamination and adulteration. At present, there is a need of more research to establish effective and safe doses of CBD. Clinicians need to monitor new data from ongoing CBD trials, but at present there is no hard evidence supporting effectiveness of CBD in various medical conditions, apart from epilepsy

Intermittent fasting – a novel approach to treating overweight and obesity? – meta-analysis and literature review

Introduction Intermittent fasting (IF) is a form of dietary intervention that includes periods of regular calorie intake alternated with periods of fasting. IF has gained a lot of attention as a potential approach to treating metabolic syndrome-related diseases. Therefore, health care professionals need to be able to provide their patients with evidence-based information on IF. The aim of this article is to review data on effectiveness of IF in weight loss, especially in comparison with calorie restriction. MethodsPubMed and Google Scholar databases were searched for studies published from 1.01.2017 to 31.12.2022 that included phrases “intermittent fasting” or “alternate day fasting”, “intermittent fasting obesity”, “alternate day fasting obesity”. Intervention studies on obese or overweight patients were included. We excluded studies of short duration and studies that focused on intercurrent medical conditions. In total, 14 articles that suited those criteria were identified. ResultsIntermittent fasting induces pronounced metabolic changes in the body due to strict and time-limited restriction of calorie intake and in animal models was proved to prolong lifespan and modulate tumorigenesis and aging. It is a proposed new approach to treating obesity, which is a a major risk factor for cardiovascular diseases and diabetes. ConclusionsIn our study, IF was found as effective, but not superior to calorie restriction in reducing body mass, improving body composition and reducing other cardiometabolic risk factors. Our findings are consistent with other recent systematic reviews. Further research is needed to directly compare various IF regimens and determine patients’ characteristics that may be associated with more successful implementation of intermittent fasting regimens

Intermittent fasting – a novel approach to treating overweight and obesity? – meta-analysis and literature review

Introduction Intermittent fasting (IF) is a form of dietary intervention that includes periods of regular calorie intake alternated with periods of fasting. IF has gained a lot of attention as a potential approach to treating metabolic syndrome-related diseases. Therefore, health care professionals need to be able to provide their patients with evidence-based information on IF. The aim of this article is to review data on effectiveness of IF in weight loss, especially in comparison with calorie restriction. Methods PubMed and Google Scholar databases were searched for studies published from 1.01.2017 to 31.12.2022 that included phrases “intermittent fasting” or “alternate day fasting”, “intermittent fasting obesity”, “alternate day fasting obesity”. Intervention studies on obese or overweight patients were included. We excluded studies of short duration and studies that focused on intercurrent medical conditions. In total, 14 articles that suited those criteria were identified. Results Intermittent fasting induces pronounced metabolic changes in the body due to strict and time-limited restriction of calorie intake and in animal models was proved to prolong lifespan and modulate tumorigenesis and aging. It is a proposed new approach to treating obesity, which is a a major risk factor for cardiovascular diseases and diabetes. Conclusions In our study, IF was found as effective, but not superior to calorie restriction in reducing body mass, improving body composition and reducing other cardiometabolic risk factors. Our findings are consistent with other recent systematic reviews. Further research is needed to directly compare various IF regimens and determine patients’ characteristics that may be associated with more successful implementation of intermittent fasting regimens