1. modified natural macromolecules
Biomaterials
ceramics
metals
Classes
Biomaterials
composites
synthetic polymers
modified natural macromolecules

2. Biomaterials Materiais Vantagens Desvantagens Aplicações clínicas
Polímeros
Elasticidade; fácil de preparar; baixa densidade
Baixa força mecânica; degradação
Suturas; veias; dentes; tendões artificiais
Metais
Força de tensão elevada; alta resistência ao uso
Baixa biocompatibilidadecorrosão em meios fisiológicos; alta densidade
Ortopedia (parafusos, placas); implantes dentários
Cerâmicos
Boa compatibilidade resistência à corrosão; inerte
Baixa força de impacto; difícil de fabricar; alta densidade
Próteses; dentes
Compósitos
Cerâmicos revestidos com metal
Difícil de fabricar
Válvulas artificiais

3. > 2000 Romans, Chineses, Aztec
Biomaterials
History
> Romans, Chineses, Aztec
Teeth gold
Glass eye
20th century Plastics
PMMA , Dentistry
PMMA nd World War
Lenses

4. Resistance to degradation Chemical and Physical Characterization
Biomaterials
Preparation
Choice
Biomaterials
Biocompatibility
Resistance to degradation
Chemical and Physical Characterization

5. Considerations Biomaterials
(The effect of the organism on the implant and the effect of the implant on the organism)
Considerations
1- The material must not leach or release soluble components into the living system
2- The living systems must not degrade the implant, unless this degradation is intentional
3- Biocompatible
4- Non toxic and non carcinogenic
5- Chemically inert and stable
6- Right mechanical strength
7- Right density
8- Relatively inexpensive, reproducible and easy to fabricate and process on a large scale

6. Implants Biomaterials
Success of Biomaterials or implants is highly dependent on three major factors
Properties and biocompatibility of the implant
Condition of the recipient
Competency of the surgeon who implants

7. Ideal Biomaterial Biomaterials Must NOT cause Thrombosis
Alteration of plasma proteins
Destruction of enzymes
Adverse immune responses
Damage to adjacent tissues
Cancer
Toxic or allergic reactions

8. Sterilization Biomaterials Steam (15-30 minutes at 121ºC)
Ethylene oxide (48 hours at 30-50ºC)
Radiation (UV or Co – 25KGy)
Electron beam (25KGy)
Dry heat (> 140ºC)
New technologies (ClO2, plasma, ozone, X-ray)

9. Biomaterials Characterization
Chemical
Physical
Biocompatibility
“in vivo”
“in vitro”
Surface characterization

10. Applications Biomaterials Orthopedy Ophtalmology Dentistry Cosmetic
Cardiology

11. Biomaterials
Cardiology
Stent

12. Biomaterials
Stent application

13. Biomaterials
Heart valves

14. Improve blood compatibility
Biomaterials
Improve blood compatibility
Protect the
body from
the device
Surface
Modification
Increase or decrease
wettability of the surface
Reduce
(or increase)
tissue adhesion
Protect the
device from
the body
Add biologically
active substances to
the surface layer
Modify the
appearance
Alter the
protein adsortion
characteristics

15. Biopolymers Biostable Polymers Biodegradable Polymers
Chemically and mechanically stable in biological medium for extended period of time, which is desired for long term applications – hip implant
Biodegradable Polymers
Which are required during limited time period – drug delivery system

16. Biomedical Applications of Polymeric Materials
Biopolymers
Biomedical Applications of Polymeric Materials
Medical - Surgical Applications
- Syringes
- Bandages
- Sutures, etc...
Systems with therapeutic function
- Drug delivery systems
- Diagnostics: Biosensors

17. Biopolymers Systems to Replace or Assist Malfunctioning Body Parts
- Contact lenses
- Artificial teeth
- Insulin pumps
- Artificial kidney
- Artificial heart
- Orthopeadic protheses
- Cardiovascular implants

18. Biomedical Applications of Synthetic Polymers
Biopolymers
Biomedical Applications of Synthetic Polymers
Orthopaedics (18%)
Dialysis (6%)
Ophthalmic (4%)
Surgery (3%)
Dental (2%)
Cardiology (26%)
Controlled drug delivery systems (25%)

19. Methacrylic and Acrylic Polymers
Biopolymers
Methacrylic and Acrylic Polymers
CH CH
COOH
CH C
CH3
COOH
acrylic acid
- Contact lenses
- Bone cements
- Dental implants
methacrylic acid

20. Composition of Bone Cement
Biopolymers
Composition of Bone Cement

21. Preparation of the Cement
Biopolymers
Preparation of the Cement

22. Biopolymers
Hip Joint
PMMA
Metal PE

23. Biopolymers Poly(urethanes)
OCN – diisocyanate – N – C – O - polyether – O – C – N – diisocyanate - NCO
H O
O H
Artificial hearts
Blood bags
Catheters
Heart valves
Pacemaker leads
Tubing for grafts
Ligament replacements

24. Some Biodegradable Polymeric Biomaterials
Biopolymers
Some Biodegradable Polymeric Biomaterials

25. poly(dimethylsiloxane)
Biopolymers
Silicone Polymers
( )
CH3 Si O n
Plastic surgical materials
Breast implants
Adhesives
Heart valves
Oxygenators
Contact lenses
Catheters
Blood pumps
poly(dimethylsiloxane)

26. Biomaterials
Hydrogels

27. Hydrogels Biomaterials Background
Hydrogels are water-swollen, cross-linked polymeric structures produced by the simple reaction of one or more monomers or by association bonds such as hydrogen bonds and strong van der Waals interactions between chains.
The title of my presentation is “Biocatalytic Hydrogels” and reports the work that I have doing during my PhD project under supervision of Prof. Helena Gil and Prof. Jontahan Dordick in the Chemical Engineering Department of Coimbra University and Rensselear Polytechnic Institute.
What is hydrogels ?
Basically Hydrogels are three-dimensional polymer network that do not disolve in water but are able to swell and retain a significant amount of water.
There are several applications for hydrogels such as ...
But the physical properties of gels make them attractive for a variety of biomedical and pharmaceutical applications such as...
We are mainly interested to use hydrogels for biomedical purposes such as networks to grow cells for tissue enginnering and small solutes and protein controlled-release systems.

28. Hydrogels Biomaterials Applications:
Biotechnology and material fields:
super-absorbent diapers; water-treatment additives; membranes for separating biological compounds such as proteins; matrix for affinity chromatography and gel electrophoresis.

29. Hydrogels Biomaterials Applications: Biomedical field:
contact lenses; synthetic joint cartilage; matrix in bone surgery; networks to grow cells for tissue enginnering; small solutes and protein controlled-release systems.

30. Applications Biomaterials
Hydrogels as drug delivery systems and scaffolds for tissue engineering
Small drugs, Proteins, Growth factors, Plasmid DNA
Cell-adhesion factors
Cells

31. Biomaterials
They perform very well when implanted sub-cutaneously, intramuscularly or peritonealy.
This is confirmed by implantation studies up to one year duration on various types of animals.

32. Advantages of hydrogels as Biomaterials
Permeable for aqueous solids
Permeable to body fluids
Soft when hydrated
Low adherance to tissue and mucuous membranes
Water absorption , swelling
Permeable for drug solutions

33. Hydrogels cathegories by
Biomaterials
Hydrogels cathegories by
origin
Natural
Synthetic
water content
Low swelling (20-50%)
Medium swelling (50-90%)
High swelling (90-99,5%)
Super-absorbent (>99,5%)

34. Hydrogels cathegories by
Biomaterials
Hydrogels cathegories by
processing
Thermoset (covalently crosslinked)
Thermoplastic (physicaly cross-linked, solid meltable)
chemical stability
Biodegradable
Bioerodible
Non-degradable

35. Essential structure features of hydrogels
Biomaterials
Essential structure features of hydrogels
Polymer chain of hydrophilic units with a broad range of chemical structure but forming strong H-bonds with water
Hydrophilic chains tied together by multiple links of covalent or physical nature but stable in presence of water