Sustainable UV-Crosslinkable Acrylic Pressure-Sensitive Adhesives for Medical Application

This study aimed to investigate the potential of photoreactive acrylate patches as systems for transdermal drug delivery, in particular, using more renewable alternatives and more environmentally friendly synthesis routes of transdermal patches. Therefore, the aim of this study was to develop a transdermal patch containing ibuprofen and investigate its performance in vitro through the pigskin. Transparent patches were prepared using four acrylate copolymers with an incorporated photoinitiator. Two types of transdermal patches based on the photocrosslinking acrylic prepolymers with isobornyl methacrylate as biocomponent and monomer increasing Tg (“hard”) were manufactured. The obtained patches were characterized for their adhesive properties and tested for permeability of the active substance. It turns out that patches whose adhesive matrix is photoreactive polyacrylate copolymers have a higher cohesion than patches from commercial adhesives, while the modification of the copolymers with isobornyl methacrylate resulted in an improvement in adhesion and tack. This study demonstrates the feasibility of developing photoreactive acrylic-based transdermal patches that contain biocomponents that can deliver a therapeutically relevant dose of ibuprofen.

Comparative profiling of biofilm-production, quorum sensing system and virulence genes in human and ovine non-aureus staphylococci

Background: This study assessed the genetic characteristics shared by non-aureus staphylococci (NAS) responsible for human infections and those causing mastitis in dairy ewes. In a collaboration between animal and human health care professionals, we collected and identified 125 ovine and 70 human NAS isolates and compared them for biofilm production, presence of autolysins, microbial surface components recognizing adhesive matrix molecules (MSCRAMMS), pyrogenic toxins, and agr alleles regulating quorum-sensing systems. Ovine NAS included: S. epidermidis (57), S. chromogenes (29), S. haemolyticus (17), S. simulans (8), S. caprae (6), S. warneri (5), S. saprophyticus, S. intermedius, and S. muscae (1 each) while human NAS included: S. haemolyticus (28), S. epidermidis (26), S. hominis (4), S. lugdunensis (4), S. capitis (3), S. warneri (2), S. xylosus, S. pasteuri, and S. saprophyticus subsp. bovis (1 each).Results: Based on colony characteristics on Congo Red Agar, 4 (3.2%) ovine, and 49 (70%) human isolates produced biofilm. Few S. epidermidis isolates harbored the icaA/D genes coding for the polysaccharide intercellular adhesin (PIA) and the bhp, aap, and embp genes coding biofilm accumulation proteins. PCR amplification of the genes coding for autolysins (atlE and aae), microbial surface components recognizing adhesive matrix molecules (MSCRAMMs, sdrG and sdrF), enterotoxins (sea, seb, sec, sed, and see), and the toxic shock syndrome toxin (tsst), revealed that 40%, 39.2%, 47.2% and 52.8% of the sheep isolates carried atlE, aae, sdrF and sdrG, respectively, against 37.1%, 42.8%, 32.8%, and 60% of human isolates. Enterotoxins and tsst were not detected. Fifty-nine sheep isolates (all S. epidermidis, 1 S. chromogenes, and 1 S. haemolyticus) and 27 human NAS (all S. epidermidis and 1 S. warneri) were positive for the accessory gene regulator (agr), responsible for the regulation of virulence factors: agr-3se (57.8%) followed by agr-1se (36.8%) predominated in sheep, while agr-1se (65.4%), followed by agr-2se (34.6%) predominated in humans.Conclusions: This comparative study provided a detailed characterization of the putative virulence genes present in human and ovine NAS and indicated that the ability to form biofilms, observed mainly in human S. epidermidis, could be a major virulence factor facilitating colonization, infection, diffusion, and resistance.

Composition of the Holdfast Polysaccharide fromCaulobacter crescentus

ABSTRACTSurface colonization is central to the lifestyles of many bacteria. Exploiting surface niches requires sophisticated systems for sensing and attaching to solid materials.Caulobacter crescentussynthesizes a polysaccharide-based adhesin known as the holdfast at one of its cell poles, which enables tight attachment to exogenous surfaces. The genes required for holdfast biosynthesis have been analyzed in detail, but difficulties in isolating analytical quantities of the adhesin have limited efforts to characterize its chemical structure. In this report, we describe a method to extract the holdfast fromC. crescentuscultures and present a survey of its carbohydrate content. Glucose, 3-O-methylglucose, mannose,N-acetylglucosamine, and xylose were detected in our extracts. Our results provide evidence that the holdfast contains a 1,4-linked backbone of glucose, mannose,N-acetylglucosamine, and xylose that is decorated with branches at the C-6 positions of glucose and mannose. By defining the monosaccharide components in the polysaccharide, our work establishes a framework for characterizing enzymes in the holdfast pathway and provides a broader understanding of how polysaccharide adhesins are built.IMPORTANCETo colonize solid substrates, bacteria often deploy dedicated adhesins that facilitate attachment to surfaces.Caulobacter crescentusinitiates surface colonization by secreting a carbohydrate-based adhesin called the holdfast. Because little is known about the chemical makeup of the holdfast, the pathway for its biosynthesis and the physical basis for its unique adhesive properties are poorly understood. This study outlines a method to extract theC. crescentusholdfast and describes the monosaccharide components contained within the adhesive matrix. The composition analysis adds to our understanding of the chemical basis for holdfast attachment and provides missing information needed to characterize enzymes in the biosynthetic pathway.

KEBUTUHAN ENERGI PADA PEMBUATAN PAPAN PARTIKEL DARI TANDAN KOSONG KELAPA SAWIT, SERBUK KULIT PINUS DAN AKASIA

Human needs for wood as building materials or furniture continue to increase along with the increase in population, while the availability of wood in the forest is both limited in number and quality. This affects the particle board industry which is increasingly difficult to get good quality solid wood. One alternative to replace wood particles is Oil Palm Empty Bunches which has enormous potential to be used in the engineering field, especially as raw material for making particle boards, by utilizing acacia bark as an adhesive (matrix). To make particle board energy is needed in the manufacturing process. The energy needed in the process of making particle boards is 47,446,211.61 Joules for 25 particle boards or for 1 board for 1,897,848.46 Joules. If converted to Rupiah, the value of one particle board is Rp. 5030. When compared with factory-made prices with a size of 120 cm x 250 cm with a thickness of 1.2 cm at a price of Rp. 90,000, the particle boards that have been made are more expensive than factory-made ones.